diff --git a/tests/CommunityToolkit.Aspire.GoFeatureFlag.Tests/GoFeatureFlagContainerFixture.cs b/tests/CommunityToolkit.Aspire.GoFeatureFlag.Tests/GoFeatureFlagContainerFixture.cs
index 7e7dfbab9..521f98f94 100644
--- a/tests/CommunityToolkit.Aspire.GoFeatureFlag.Tests/GoFeatureFlagContainerFixture.cs
+++ b/tests/CommunityToolkit.Aspire.GoFeatureFlag.Tests/GoFeatureFlagContainerFixture.cs
@@ -28,7 +28,7 @@ public async ValueTask InitializeAsync()
         if (RequiresDockerAttribute.IsSupported)
         {
             var source = Path.GetFullPath("./goff", Directory.GetCurrentDirectory());
-            Container = new ContainerBuilder($"{GoFeatureFlagContainerImageTags.Registry}/{GoFeatureFlagContainerImageTags.Image}:{GoFeatureFlagContainerImageTags.Tag}")
+            Container = new ContainerBuilder($"{TestContainerRegistry.Resolve(GoFeatureFlagContainerImageTags.Registry)}/{GoFeatureFlagContainerImageTags.Image}:{GoFeatureFlagContainerImageTags.Tag}")
               .WithPortBinding(1031, true)
               .WithWaitStrategy(Wait.ForUnixContainer().UntilHttpRequestIsSucceeded(r => r.ForPath("/health").ForPort(1031)))
               .WithBindMount(source, "/goff")
diff --git a/tests/CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects.Tests/SqlServerContainerFixture.cs b/tests/CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects.Tests/SqlServerContainerFixture.cs
index 774c1f27f..78b88b67a 100644
--- a/tests/CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects.Tests/SqlServerContainerFixture.cs
+++ b/tests/CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects.Tests/SqlServerContainerFixture.cs
@@ -1,4 +1,5 @@
-using Testcontainers.MsSql;
+using CommunityToolkit.Aspire.Testing;
+using Testcontainers.MsSql;
 
 namespace CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects.Tests;
 
@@ -25,7 +26,7 @@ public async ValueTask DisposeAsync()
 
     public static async Task<MsSqlContainer> CreateContainerAsync()
     {
-        var container = new MsSqlBuilder($"{Registry}/{Image}:{Tag}")
+        var container = new MsSqlBuilder($"{TestContainerRegistry.Resolve(Registry)}/{Image}:{Tag}")
             .Build();
         await container.StartAsync();
 
diff --git a/tests/CommunityToolkit.Aspire.KurrentDB.Tests/KurrentDBContainerFixture.cs b/tests/CommunityToolkit.Aspire.KurrentDB.Tests/KurrentDBContainerFixture.cs
index bf7214c3a..99bd45b52 100644
--- a/tests/CommunityToolkit.Aspire.KurrentDB.Tests/KurrentDBContainerFixture.cs
+++ b/tests/CommunityToolkit.Aspire.KurrentDB.Tests/KurrentDBContainerFixture.cs
@@ -27,7 +27,7 @@ public async ValueTask InitializeAsync()
     {
         if (RequiresDockerAttribute.IsSupported)
         {
-            Container = new ContainerBuilder($"{KurrentDBContainerImageTags.Registry}/{KurrentDBContainerImageTags.Image}:{KurrentDBContainerImageTags.Tag}")
+            Container = new ContainerBuilder($"{TestContainerRegistry.Resolve(KurrentDBContainerImageTags.Registry)}/{KurrentDBContainerImageTags.Image}:{KurrentDBContainerImageTags.Tag}")
               .WithPortBinding(2113, true)
               .WithWaitStrategy(Wait.ForUnixContainer().UntilHttpRequestIsSucceeded(r => r.ForPort(2113)))
               .WithEnvironment("KURRENTDB_CLUSTER_SIZE", "1")
diff --git a/tests/CommunityToolkit.Aspire.Meilisearch.Tests/MeilisearchContainerFixture.cs b/tests/CommunityToolkit.Aspire.Meilisearch.Tests/MeilisearchContainerFixture.cs
index ff8149656..907f8f2e2 100644
--- a/tests/CommunityToolkit.Aspire.Meilisearch.Tests/MeilisearchContainerFixture.cs
+++ b/tests/CommunityToolkit.Aspire.Meilisearch.Tests/MeilisearchContainerFixture.cs
@@ -45,7 +45,7 @@ public async ValueTask InitializeAsync()
             //The master key must be at least 16-bytes-long and composed of valid UTF-8 characters.
             _masterKey = param.GetDefaultValue();
 
-            Container = new ContainerBuilder($"{MeilisearchContainerImageTags.Registry}/{MeilisearchContainerImageTags.Image}:{MeilisearchContainerImageTags.Tag}")
+            Container = new ContainerBuilder($"{TestContainerRegistry.Resolve(MeilisearchContainerImageTags.Registry)}/{MeilisearchContainerImageTags.Image}:{MeilisearchContainerImageTags.Tag}")
               .WithPortBinding(7700, true)
               .WithWaitStrategy(Wait.ForUnixContainer().UntilHttpRequestIsSucceeded(r => r.ForPort(7700)))
               .WithEnvironment("MEILI_MASTER_KEY", _masterKey)
diff --git a/tests/CommunityToolkit.Aspire.OllamaSharp.Tests/OllamaContainerFeature.cs b/tests/CommunityToolkit.Aspire.OllamaSharp.Tests/OllamaContainerFeature.cs
index 09c18e7aa..ab0e6884a 100644
--- a/tests/CommunityToolkit.Aspire.OllamaSharp.Tests/OllamaContainerFeature.cs
+++ b/tests/CommunityToolkit.Aspire.OllamaSharp.Tests/OllamaContainerFeature.cs
@@ -23,7 +23,7 @@ public async ValueTask InitializeAsync()
     {
         if (RequiresDockerAttribute.IsSupported)
         {
-            Container = new ContainerBuilder($"{OllamaContainerImageTags.Registry}/{OllamaContainerImageTags.Image}:{OllamaContainerImageTags.Tag}")
+            Container = new ContainerBuilder($"{TestContainerRegistry.Resolve(OllamaContainerImageTags.Registry)}/{OllamaContainerImageTags.Image}:{OllamaContainerImageTags.Tag}")
               .WithPortBinding(11434, true)
               .WithWaitStrategy(Wait.ForUnixContainer().UntilHttpRequestIsSucceeded(r => r.ForPort(11434)))
               .Build();
diff --git a/tests/CommunityToolkit.Aspire.SurrealDb.Tests/SurrealDbContainerFixture.cs b/tests/CommunityToolkit.Aspire.SurrealDb.Tests/SurrealDbContainerFixture.cs
index a12c4d5c4..a332b0618 100644
--- a/tests/CommunityToolkit.Aspire.SurrealDb.Tests/SurrealDbContainerFixture.cs
+++ b/tests/CommunityToolkit.Aspire.SurrealDb.Tests/SurrealDbContainerFixture.cs
@@ -48,7 +48,7 @@ public async ValueTask InitializeAsync()
 
             _password = paramGenerator.GetDefaultValue();
 
-            Container = new ContainerBuilder($"{SurrealDbContainerImageTags.Registry}/{SurrealDbContainerImageTags.Image}:{SurrealDbContainerImageTags.Tag}")
+            Container = new ContainerBuilder($"{TestContainerRegistry.Resolve(SurrealDbContainerImageTags.Registry)}/{SurrealDbContainerImageTags.Image}:{SurrealDbContainerImageTags.Tag}")
                 .WithPortBinding(_port, true)
                 .WithWaitStrategy(Wait.ForUnixContainer().UntilHttpRequestIsSucceeded(r => r.ForPort(_port).ForPath("/health")))
                 .WithEnvironment("SURREAL_USER", _username)
diff --git a/tests/CommunityToolkit.Aspire.Testing/TestContainerRegistry.cs b/tests/CommunityToolkit.Aspire.Testing/TestContainerRegistry.cs
new file mode 100644
index 000000000..f4394fd52
--- /dev/null
+++ b/tests/CommunityToolkit.Aspire.Testing/TestContainerRegistry.cs
@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace CommunityToolkit.Aspire.Testing;
+
+/// <summary>
+/// Helper for tests that create containers directly via the Testcontainers library (i.e. not through
+/// Aspire's container resource model) so that they can also be routed through a custom container registry.
+/// </summary>
+public static class TestContainerRegistry
+{
+    private const string DockerHubRegistry = "docker.io";
+
+    /// <summary>
+    /// Resolves the registry to use for a Testcontainers image reference. If <paramref name="registry"/> is the
+    /// default Docker Hub registry and the <c>CUSTOM_CONTAINER_REGISTRY</c> environment variable is set, the
+    /// custom registry is returned instead to avoid Docker Hub rate limiting. Otherwise, <paramref name="registry"/>
+    /// is returned unchanged.
+    /// </summary>
+    /// <param name="registry">The registry the image would otherwise be pulled from.</param>
+    public static string Resolve(string registry)
+    {
+        string? customRegistry = Environment.GetEnvironmentVariable("CUSTOM_CONTAINER_REGISTRY");
+
+        return registry == DockerHubRegistry && !string.IsNullOrEmpty(customRegistry)
+            ? customRegistry
+            : registry;
+    }
+}