diff --git a/src/GovUk.Education.ExploreEducationStatistics.Content.Api.Tests/Controllers/ThemeControllerCachingTests.cs b/src/GovUk.Education.ExploreEducationStatistics.Content.Api.Tests/Controllers/ThemeControllerCachingTests.cs
new file mode 100644
index 00000000000..a284f8f4642
--- /dev/null
+++ b/src/GovUk.Education.ExploreEducationStatistics.Content.Api.Tests/Controllers/ThemeControllerCachingTests.cs
@@ -0,0 +1,97 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using GovUk.Education.ExploreEducationStatistics.Common.Cache;
+using GovUk.Education.ExploreEducationStatistics.Common.Tests.Extensions;
+using GovUk.Education.ExploreEducationStatistics.Common.Tests.Fixtures;
+using GovUk.Education.ExploreEducationStatistics.Content.Api.Cache;
+using GovUk.Education.ExploreEducationStatistics.Content.Api.Controllers;
+using GovUk.Education.ExploreEducationStatistics.Content.Services.Interfaces;
+using GovUk.Education.ExploreEducationStatistics.Content.Services.Interfaces.Cache;
+using GovUk.Education.ExploreEducationStatistics.Content.Services.ViewModels;
+using Moq;
+using NCrontab;
+using Xunit;
+using static GovUk.Education.ExploreEducationStatistics.Common.Cache.CronSchedules;
+using static GovUk.Education.ExploreEducationStatistics.Common.Services.CollectionUtils;
+using static GovUk.Education.ExploreEducationStatistics.Common.Tests.Utils.MockUtils;
+using static Moq.MockBehavior;
+using static Newtonsoft.Json.JsonConvert;
+
+namespace GovUk.Education.ExploreEducationStatistics.Content.Api.Tests.Controllers;
+
+[Collection(CacheServiceTests)]
+public class ThemeControllerCachingTests : CacheServiceTestFixture
+{
+    private readonly IList<ThemeViewModel> _themes = ListOf(
+        new ThemeViewModel(Guid.NewGuid(), "slug1", "title1", "summary1"),
+        new ThemeViewModel(Guid.NewGuid(), "slug2", "title2", "summary2"));
+    
+    [Fact]
+    public async Task ListThemes_NoCachedEntryExists()
+    {
+        var themeService = new Mock<IThemeService>(Strict);
+        
+        MemoryCacheService
+            .Setup(s => s.GetItem(
+                new ListThemesCacheKey(),
+                typeof(IList<ThemeViewModel>)))
+            .Returns(null);
+
+        var expectedCacheConfiguration = new MemoryCacheConfiguration(
+            10, CrontabSchedule.Parse(HalfHourlyExpirySchedule));
+        
+        MemoryCacheService
+            .Setup(s => s.SetItem<object>(
+                new ListThemesCacheKey(),
+                _themes,
+                ItIs.DeepEqualTo(expectedCacheConfiguration),
+                null));
+        
+        themeService
+            .Setup(s => s.ListThemes())
+            .ReturnsAsync(_themes);
+        
+        var controller = BuildController(themeService.Object);
+
+        var result = await controller.ListThemes();
+        
+        VerifyAllMocks(MemoryCacheService, themeService);
+
+        Assert.Equal(_themes, result);
+    }
+    
+    [Fact]
+    public async Task ListThemes_CachedEntryExists()
+    {
+        MemoryCacheService
+            .Setup(s => s.GetItem(
+                new ListThemesCacheKey(),
+                typeof(IList<ThemeViewModel>)))
+            .Returns(_themes);
+        
+        var controller = BuildController();
+
+        var result = await controller.ListThemes();
+        
+        VerifyAllMocks(MemoryCacheService);
+
+        Assert.Equal(_themes, result);
+    }
+    
+    [Fact]
+    public void ThemeViewModelList_SerializeAndDeserialize()
+    {
+        var converted = DeserializeObject<List<ThemeViewModel>>(SerializeObject(_themes));
+        converted.AssertDeepEqualTo(_themes);
+    }
+
+    private static ThemeController BuildController(IThemeService? themeService = null)
+    {
+        return new(
+            Mock.Of<IMethodologyCacheService>(),
+            themeService ?? Mock.Of<IThemeService>(Strict)
+        );
+    }
+}
diff --git a/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Cache/ListThemesCacheKey.cs b/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Cache/ListThemesCacheKey.cs
new file mode 100644
index 00000000000..7bf2f175b21
--- /dev/null
+++ b/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Cache/ListThemesCacheKey.cs
@@ -0,0 +1,8 @@
+using GovUk.Education.ExploreEducationStatistics.Common.Cache.Interfaces;
+
+namespace GovUk.Education.ExploreEducationStatistics.Content.Api.Cache;
+
+public record ListThemesCacheKey : IMemoryCacheKey
+{
+    public string Key => GetType().Name;
+}
\ No newline at end of file
diff --git a/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Controllers/ThemeController.cs b/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Controllers/ThemeController.cs
index be5a50409e8..7f28acd503b 100644
--- a/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Controllers/ThemeController.cs
+++ b/src/GovUk.Education.ExploreEducationStatistics.Content.Api/Controllers/ThemeController.cs
@@ -2,11 +2,14 @@
 using System.Collections.Generic;
 using System.Net.Mime;
 using System.Threading.Tasks;
+using GovUk.Education.ExploreEducationStatistics.Common.Cache;
 using GovUk.Education.ExploreEducationStatistics.Common.Extensions;
+using GovUk.Education.ExploreEducationStatistics.Content.Api.Cache;
 using GovUk.Education.ExploreEducationStatistics.Content.Services.Interfaces;
 using GovUk.Education.ExploreEducationStatistics.Content.Services.Interfaces.Cache;
 using GovUk.Education.ExploreEducationStatistics.Content.Services.ViewModels;
 using Microsoft.AspNetCore.Mvc;
+using static GovUk.Education.ExploreEducationStatistics.Common.Cache.CronSchedules;
 
 namespace GovUk.Education.ExploreEducationStatistics.Content.Api.Controllers
 {
@@ -33,6 +36,7 @@ public async Task<ActionResult<List<AllMethodologiesThemeViewModel>>> GetMethodo
                 .HandleFailuresOrOk();
         }
 
+        [MemoryCache(typeof(ListThemesCacheKey), durationInSeconds: 10, expiryScheduleCron: HalfHourlyExpirySchedule)]
         [HttpGet("themes")]
         public async Task<IList<ThemeViewModel>> ListThemes()
         {