diff --git a/api/CourseRegistration.API/Controllers/DownloadController.cs b/api/CourseRegistration.API/Controllers/DownloadController.cs
new file mode 100644
index 0000000..3e944d5
--- /dev/null
+++ b/api/CourseRegistration.API/Controllers/DownloadController.cs
@@ -0,0 +1,143 @@
+using Microsoft.AspNetCore.Mvc;
+using CourseRegistration.Application.Interfaces;
+using System.Text;
+
+namespace CourseRegistration.API.Controllers;
+
+/// <summary>
+/// Controller for downloading course, student, and registration data as CSV files
+/// </summary>
+[ApiController]
+[Route("api/[controller]")]
+public class DownloadController : ControllerBase
+{
+    private readonly ICourseService _courseService;
+    private readonly IStudentService _studentService;
+    private readonly IRegistrationService _registrationService;
+    private readonly ILogger<DownloadController> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the DownloadController
+    /// </summary>
+    public DownloadController(
+        ICourseService courseService,
+        IStudentService studentService,
+        IRegistrationService registrationService,
+        ILogger<DownloadController> logger)
+    {
+        _courseService = courseService ?? throw new ArgumentNullException(nameof(courseService));
+        _studentService = studentService ?? throw new ArgumentNullException(nameof(studentService));
+        _registrationService = registrationService ?? throw new ArgumentNullException(nameof(registrationService));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    /// <summary>
+    /// Downloads all courses as a CSV file
+    /// </summary>
+    /// <returns>CSV file containing course data</returns>
+    [HttpGet("courses")]
+    [ProducesResponseType(typeof(FileResult), StatusCodes.Status200OK)]
+    public async Task<IActionResult> DownloadCourses()
+    {
+        _logger.LogInformation("Downloading courses as CSV");
+
+        var result = await _courseService.GetCoursesAsync(page: 1, pageSize: int.MaxValue);
+        var courses = result.Items;
+
+        var csv = new StringBuilder();
+        csv.AppendLine("CourseId,CourseName,Description,InstructorName,StartDate,EndDate,Schedule,CurrentEnrollment,IsActive,CreatedAt");
+
+        foreach (var course in courses)
+        {
+            csv.AppendLine(string.Join(",",
+                course.CourseId,
+                EscapeCsvField(course.CourseName),
+                EscapeCsvField(course.Description ?? string.Empty),
+                EscapeCsvField(course.InstructorName),
+                course.StartDate.ToString("yyyy-MM-dd"),
+                course.EndDate.ToString("yyyy-MM-dd"),
+                EscapeCsvField(course.Schedule),
+                course.CurrentEnrollment,
+                course.IsActive,
+                course.CreatedAt.ToString("yyyy-MM-dd")));
+        }
+
+        var bytes = Encoding.UTF8.GetBytes(csv.ToString());
+        return File(bytes, "text/csv", $"courses_{DateTime.UtcNow:yyyyMMdd}.csv");
+    }
+
+    /// <summary>
+    /// Downloads all students as a CSV file
+    /// </summary>
+    /// <returns>CSV file containing student data</returns>
+    [HttpGet("students")]
+    [ProducesResponseType(typeof(FileResult), StatusCodes.Status200OK)]
+    public async Task<IActionResult> DownloadStudents()
+    {
+        _logger.LogInformation("Downloading students as CSV");
+
+        var result = await _studentService.GetStudentsAsync(page: 1, pageSize: int.MaxValue);
+        var students = result.Items;
+
+        var csv = new StringBuilder();
+        csv.AppendLine("StudentId,FirstName,LastName,Email,PhoneNumber,DateOfBirth,CreatedAt");
+
+        foreach (var student in students)
+        {
+            csv.AppendLine(string.Join(",",
+                student.StudentId,
+                EscapeCsvField(student.FirstName),
+                EscapeCsvField(student.LastName),
+                EscapeCsvField(student.Email),
+                EscapeCsvField(student.PhoneNumber ?? string.Empty),
+                student.DateOfBirth.ToString("yyyy-MM-dd"),
+                student.CreatedAt.ToString("yyyy-MM-dd")));
+        }
+
+        var bytes = Encoding.UTF8.GetBytes(csv.ToString());
+        return File(bytes, "text/csv", $"students_{DateTime.UtcNow:yyyyMMdd}.csv");
+    }
+
+    /// <summary>
+    /// Downloads all registrations as a CSV file
+    /// </summary>
+    /// <returns>CSV file containing registration data</returns>
+    [HttpGet("registrations")]
+    [ProducesResponseType(typeof(FileResult), StatusCodes.Status200OK)]
+    public async Task<IActionResult> DownloadRegistrations()
+    {
+        _logger.LogInformation("Downloading registrations as CSV");
+
+        var result = await _registrationService.GetRegistrationsAsync(page: 1, pageSize: int.MaxValue);
+        var registrations = result.Items;
+
+        var csv = new StringBuilder();
+        csv.AppendLine("RegistrationId,StudentId,StudentName,CourseId,CourseName,RegistrationDate,Status,Grade,Notes");
+
+        foreach (var reg in registrations)
+        {
+            csv.AppendLine(string.Join(",",
+                reg.RegistrationId,
+                reg.StudentId,
+                EscapeCsvField(reg.Student != null ? $"{reg.Student.FirstName} {reg.Student.LastName}" : string.Empty),
+                reg.CourseId,
+                EscapeCsvField(reg.Course?.CourseName ?? string.Empty),
+                reg.RegistrationDate.ToString("yyyy-MM-dd"),
+                reg.Status,
+                reg.Grade?.ToString() ?? string.Empty,
+                EscapeCsvField(reg.Notes ?? string.Empty)));
+        }
+
+        var bytes = Encoding.UTF8.GetBytes(csv.ToString());
+        return File(bytes, "text/csv", $"registrations_{DateTime.UtcNow:yyyyMMdd}.csv");
+    }
+
+    private static string EscapeCsvField(string field)
+    {
+        if (field.Contains(',') || field.Contains('"') || field.Contains('\n') || field.Contains('\r'))
+        {
+            return $"\"{field.Replace("\"", "\"\"")}\"";
+        }
+        return field;
+    }
+}
diff --git a/api/CourseRegistration.Tests/Controllers/DownloadControllerTests.cs b/api/CourseRegistration.Tests/Controllers/DownloadControllerTests.cs
new file mode 100644
index 0000000..f08067b
--- /dev/null
+++ b/api/CourseRegistration.Tests/Controllers/DownloadControllerTests.cs
@@ -0,0 +1,408 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Logging;
+using Moq;
+using Xunit;
+using CourseRegistration.API.Controllers;
+using CourseRegistration.Application.DTOs;
+using CourseRegistration.Application.Interfaces;
+using CourseRegistration.Domain.Enums;
+
+namespace CourseRegistration.Tests.Controllers;
+
+/// <summary>
+/// Unit tests for DownloadController CSV download endpoints
+/// </summary>
+public class DownloadControllerTests
+{
+    private readonly Mock<ICourseService> _mockCourseService;
+    private readonly Mock<IStudentService> _mockStudentService;
+    private readonly Mock<IRegistrationService> _mockRegistrationService;
+    private readonly Mock<ILogger<DownloadController>> _mockLogger;
+    private readonly DownloadController _controller;
+
+    public DownloadControllerTests()
+    {
+        _mockCourseService = new Mock<ICourseService>();
+        _mockStudentService = new Mock<IStudentService>();
+        _mockRegistrationService = new Mock<IRegistrationService>();
+        _mockLogger = new Mock<ILogger<DownloadController>>();
+
+        _controller = new DownloadController(
+            _mockCourseService.Object,
+            _mockStudentService.Object,
+            _mockRegistrationService.Object,
+            _mockLogger.Object);
+    }
+
+    [Fact]
+    public async Task DownloadCourses_ReturnsFileResult_WithCsvContentType()
+    {
+        // Arrange
+        var courses = new PagedResponseDto<CourseDto>
+        {
+            Items = new List<CourseDto>
+            {
+                new CourseDto
+                {
+                    CourseId = Guid.NewGuid(),
+                    CourseName = "Introduction to CS",
+                    Description = "Basics of CS",
+                    InstructorName = "Dr. Smith",
+                    StartDate = new DateTime(2024, 1, 15),
+                    EndDate = new DateTime(2024, 5, 15),
+                    Schedule = "MWF 9:00-10:30",
+                    CurrentEnrollment = 25,
+                    IsActive = true,
+                    CreatedAt = new DateTime(2024, 1, 1)
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockCourseService
+            .Setup(s => s.GetCoursesAsync(1, int.MaxValue, null, null))
+            .ReturnsAsync(courses);
+
+        // Act
+        var result = await _controller.DownloadCourses();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        Assert.Equal("text/csv", fileResult.ContentType);
+        Assert.StartsWith("courses_", fileResult.FileDownloadName);
+        Assert.EndsWith(".csv", fileResult.FileDownloadName);
+    }
+
+    [Fact]
+    public async Task DownloadCourses_CsvContent_ContainsHeaderRow()
+    {
+        // Arrange
+        var courses = new PagedResponseDto<CourseDto>
+        {
+            Items = Enumerable.Empty<CourseDto>(),
+            TotalItems = 0
+        };
+
+        _mockCourseService
+            .Setup(s => s.GetCoursesAsync(1, int.MaxValue, null, null))
+            .ReturnsAsync(courses);
+
+        // Act
+        var result = await _controller.DownloadCourses();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        Assert.Contains("CourseId,CourseName", content);
+        Assert.Contains("InstructorName", content);
+    }
+
+    [Fact]
+    public async Task DownloadCourses_CsvContent_ContainsCourseData()
+    {
+        // Arrange
+        var courseId = Guid.NewGuid();
+        var courses = new PagedResponseDto<CourseDto>
+        {
+            Items = new List<CourseDto>
+            {
+                new CourseDto
+                {
+                    CourseId = courseId,
+                    CourseName = "Web Development",
+                    InstructorName = "Prof. Jones",
+                    StartDate = new DateTime(2024, 2, 1),
+                    EndDate = new DateTime(2024, 6, 1),
+                    Schedule = "TTh 14:00-16:00",
+                    CurrentEnrollment = 30,
+                    IsActive = true,
+                    CreatedAt = new DateTime(2024, 1, 10)
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockCourseService
+            .Setup(s => s.GetCoursesAsync(1, int.MaxValue, null, null))
+            .ReturnsAsync(courses);
+
+        // Act
+        var result = await _controller.DownloadCourses();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        Assert.Contains("Web Development", content);
+        Assert.Contains("Prof. Jones", content);
+        Assert.Contains(courseId.ToString(), content);
+    }
+
+    [Fact]
+    public async Task DownloadStudents_ReturnsFileResult_WithCsvContentType()
+    {
+        // Arrange
+        var students = new PagedResponseDto<StudentDto>
+        {
+            Items = new List<StudentDto>
+            {
+                new StudentDto
+                {
+                    StudentId = Guid.NewGuid(),
+                    FirstName = "John",
+                    LastName = "Doe",
+                    Email = "john.doe@example.com",
+                    PhoneNumber = "+1-555-0101",
+                    DateOfBirth = new DateTime(1995, 5, 15),
+                    CreatedAt = new DateTime(2024, 1, 1)
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockStudentService
+            .Setup(s => s.GetStudentsAsync(1, int.MaxValue))
+            .ReturnsAsync(students);
+
+        // Act
+        var result = await _controller.DownloadStudents();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        Assert.Equal("text/csv", fileResult.ContentType);
+        Assert.StartsWith("students_", fileResult.FileDownloadName);
+        Assert.EndsWith(".csv", fileResult.FileDownloadName);
+    }
+
+    [Fact]
+    public async Task DownloadStudents_CsvContent_ContainsHeaderRow()
+    {
+        // Arrange
+        var students = new PagedResponseDto<StudentDto>
+        {
+            Items = Enumerable.Empty<StudentDto>(),
+            TotalItems = 0
+        };
+
+        _mockStudentService
+            .Setup(s => s.GetStudentsAsync(1, int.MaxValue))
+            .ReturnsAsync(students);
+
+        // Act
+        var result = await _controller.DownloadStudents();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        Assert.Contains("StudentId,FirstName,LastName,Email", content);
+        Assert.Contains("DateOfBirth", content);
+    }
+
+    [Fact]
+    public async Task DownloadStudents_CsvContent_ContainsStudentData()
+    {
+        // Arrange
+        var studentId = Guid.NewGuid();
+        var students = new PagedResponseDto<StudentDto>
+        {
+            Items = new List<StudentDto>
+            {
+                new StudentDto
+                {
+                    StudentId = studentId,
+                    FirstName = "Jane",
+                    LastName = "Smith",
+                    Email = "jane.smith@example.com",
+                    DateOfBirth = new DateTime(1996, 8, 20),
+                    CreatedAt = new DateTime(2024, 1, 5)
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockStudentService
+            .Setup(s => s.GetStudentsAsync(1, int.MaxValue))
+            .ReturnsAsync(students);
+
+        // Act
+        var result = await _controller.DownloadStudents();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        Assert.Contains("Jane", content);
+        Assert.Contains("Smith", content);
+        Assert.Contains("jane.smith@example.com", content);
+        Assert.Contains(studentId.ToString(), content);
+    }
+
+    [Fact]
+    public async Task DownloadRegistrations_ReturnsFileResult_WithCsvContentType()
+    {
+        // Arrange
+        var registrations = new PagedResponseDto<RegistrationDto>
+        {
+            Items = new List<RegistrationDto>
+            {
+                new RegistrationDto
+                {
+                    RegistrationId = Guid.NewGuid(),
+                    StudentId = Guid.NewGuid(),
+                    CourseId = Guid.NewGuid(),
+                    RegistrationDate = DateTime.UtcNow.AddDays(-5),
+                    Status = RegistrationStatus.Confirmed,
+                    Student = new StudentDto { FirstName = "John", LastName = "Doe", Email = "john@example.com" },
+                    Course = new CourseDto { CourseName = "CS101", InstructorName = "Dr. A" }
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockRegistrationService
+            .Setup(s => s.GetRegistrationsAsync(1, int.MaxValue, null, null, null))
+            .ReturnsAsync(registrations);
+
+        // Act
+        var result = await _controller.DownloadRegistrations();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        Assert.Equal("text/csv", fileResult.ContentType);
+        Assert.StartsWith("registrations_", fileResult.FileDownloadName);
+        Assert.EndsWith(".csv", fileResult.FileDownloadName);
+    }
+
+    [Fact]
+    public async Task DownloadRegistrations_CsvContent_ContainsHeaderRow()
+    {
+        // Arrange
+        var registrations = new PagedResponseDto<RegistrationDto>
+        {
+            Items = Enumerable.Empty<RegistrationDto>(),
+            TotalItems = 0
+        };
+
+        _mockRegistrationService
+            .Setup(s => s.GetRegistrationsAsync(1, int.MaxValue, null, null, null))
+            .ReturnsAsync(registrations);
+
+        // Act
+        var result = await _controller.DownloadRegistrations();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        Assert.Contains("RegistrationId", content);
+        Assert.Contains("StudentName", content);
+        Assert.Contains("CourseName", content);
+        Assert.Contains("Status", content);
+    }
+
+    [Fact]
+    public async Task DownloadRegistrations_CsvContent_ContainsRegistrationData()
+    {
+        // Arrange
+        var registrationId = Guid.NewGuid();
+        var registrations = new PagedResponseDto<RegistrationDto>
+        {
+            Items = new List<RegistrationDto>
+            {
+                new RegistrationDto
+                {
+                    RegistrationId = registrationId,
+                    StudentId = Guid.NewGuid(),
+                    CourseId = Guid.NewGuid(),
+                    RegistrationDate = new DateTime(2024, 3, 1),
+                    Status = RegistrationStatus.Confirmed,
+                    Student = new StudentDto { FirstName = "Alice", LastName = "Brown", Email = "alice@example.com" },
+                    Course = new CourseDto { CourseName = "Advanced Math", InstructorName = "Prof. Davis" }
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockRegistrationService
+            .Setup(s => s.GetRegistrationsAsync(1, int.MaxValue, null, null, null))
+            .ReturnsAsync(registrations);
+
+        // Act
+        var result = await _controller.DownloadRegistrations();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        Assert.Contains(registrationId.ToString(), content);
+        Assert.Contains("Alice Brown", content);
+        Assert.Contains("Advanced Math", content);
+        Assert.Contains("Confirmed", content);
+    }
+
+    [Fact]
+    public async Task DownloadCourses_CsvField_EscapesCommasInFields()
+    {
+        // Arrange
+        var courses = new PagedResponseDto<CourseDto>
+        {
+            Items = new List<CourseDto>
+            {
+                new CourseDto
+                {
+                    CourseId = Guid.NewGuid(),
+                    CourseName = "Math, Science, and Art",
+                    InstructorName = "Dr. Smith",
+                    Description = "A course covering math, science",
+                    StartDate = new DateTime(2024, 1, 1),
+                    EndDate = new DateTime(2024, 6, 1),
+                    Schedule = "MWF",
+                    CreatedAt = new DateTime(2024, 1, 1)
+                }
+            },
+            TotalItems = 1
+        };
+
+        _mockCourseService
+            .Setup(s => s.GetCoursesAsync(1, int.MaxValue, null, null))
+            .ReturnsAsync(courses);
+
+        // Act
+        var result = await _controller.DownloadCourses();
+
+        // Assert
+        var fileResult = Assert.IsType<FileContentResult>(result);
+        var content = System.Text.Encoding.UTF8.GetString(fileResult.FileContents);
+        // Fields with commas should be quoted
+        Assert.Contains("\"Math, Science, and Art\"", content);
+    }
+
+    [Fact]
+    public void Constructor_ThrowsArgumentNullException_WhenCourseServiceIsNull()
+    {
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => new DownloadController(
+            null!,
+            _mockStudentService.Object,
+            _mockRegistrationService.Object,
+            _mockLogger.Object));
+    }
+
+    [Fact]
+    public void Constructor_ThrowsArgumentNullException_WhenStudentServiceIsNull()
+    {
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => new DownloadController(
+            _mockCourseService.Object,
+            null!,
+            _mockRegistrationService.Object,
+            _mockLogger.Object));
+    }
+
+    [Fact]
+    public void Constructor_ThrowsArgumentNullException_WhenRegistrationServiceIsNull()
+    {
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => new DownloadController(
+            _mockCourseService.Object,
+            _mockStudentService.Object,
+            null!,
+            _mockLogger.Object));
+    }
+}
diff --git a/api/CourseRegistration.Tests/CourseRegistration.Tests.csproj b/api/CourseRegistration.Tests/CourseRegistration.Tests.csproj
index 17b82fa..f7a658d 100644
--- a/api/CourseRegistration.Tests/CourseRegistration.Tests.csproj
+++ b/api/CourseRegistration.Tests/CourseRegistration.Tests.csproj
@@ -10,6 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="Moq" Version="4.20.70" />
     <PackageReference Include="xunit" Version="2.6.5" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
diff --git a/frontend/index.html b/frontend/index.html
index 9773824..bd3903d 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -181,6 +181,10 @@ <h2>
                             <i class="fas fa-sync-alt"></i>
                             Refresh
                         </button>
+                        <button class="btn btn-secondary" onclick="downloadCsv('courses')">
+                            <i class="fas fa-download"></i>
+                            Download CSV
+                        </button>
                         <button class="btn btn-primary" onclick="showAddCourse()">
                             <i class="fas fa-plus"></i>
                             Add New Course
@@ -230,6 +234,10 @@ <h2>
                         <i class="fas fa-sync-alt"></i>
                         Refresh
                     </button>
+                    <button class="btn btn-secondary" onclick="downloadCsv('registrations')">
+                        <i class="fas fa-download"></i>
+                        Download CSV
+                    </button>
                     <button class="btn btn-primary" onclick="showCreateRegistration()">
                         <i class="fas fa-plus"></i>
                         New Registration
diff --git a/frontend/script.js b/frontend/script.js
index 174617a..5082c8b 100644
--- a/frontend/script.js
+++ b/frontend/script.js
@@ -903,4 +903,43 @@ window.showRegistrations = showRegistrations;
 window.showCreateRegistration = showCreateRegistration;
 window.showRegistrationDetails = showRegistrationDetails;
 window.refreshRegistrations = refreshRegistrations;
-window.applyFilters = applyFilters;
\ No newline at end of file
+window.applyFilters = applyFilters;
+
+// ============================================================================
+// DOWNLOAD FUNCTIONALITY
+// ============================================================================
+
+async function downloadCsv(type) {
+    try {
+        const response = await fetch(`${API_BASE_URL}/download/${type}`);
+
+        if (!response.ok) {
+            throw new Error(`Download failed: ${response.statusText}`);
+        }
+
+        const blob = await response.blob();
+        const contentDisposition = response.headers.get('content-disposition');
+        let filename = `${type}_${new Date().toISOString().slice(0, 10)}.csv`;
+
+        if (contentDisposition) {
+            const match = contentDisposition.match(/filename=["']?([^"';\n]+)["']?/);
+            if (match) {
+                filename = match[1];
+            }
+        }
+
+        const url = URL.createObjectURL(blob);
+        const a = document.createElement('a');
+        a.href = url;
+        a.download = filename;
+        document.body.appendChild(a);
+        a.click();
+        document.body.removeChild(a);
+        setTimeout(() => URL.revokeObjectURL(url), 100);
+    } catch (error) {
+        console.error(`Error downloading ${type}:`, error);
+        showErrorModal(`Failed to download ${type}. Please try again.`);
+    }
+}
+
+window.downloadCsv = downloadCsv;
\ No newline at end of file