diff --git a/lib/analyze-action-post.js b/lib/analyze-action-post.js
index aaed462b38..50b46cfa40 100644
--- a/lib/analyze-action-post.js
+++ b/lib/analyze-action-post.js
@@ -162226,6 +162226,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/analyze-action.js b/lib/analyze-action.js
index cf0eef7f64..d676e89e1b 100644
--- a/lib/analyze-action.js
+++ b/lib/analyze-action.js
@@ -107986,6 +107986,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/autobuild-action.js b/lib/autobuild-action.js
index a5e822b8ea..e67b31036f 100644
--- a/lib/autobuild-action.js
+++ b/lib/autobuild-action.js
@@ -104275,6 +104275,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/init-action-post.js b/lib/init-action-post.js
index 000e55c0a5..9236f81b0d 100644
--- a/lib/init-action-post.js
+++ b/lib/init-action-post.js
@@ -165723,6 +165723,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/init-action.js b/lib/init-action.js
index bce9e2dfcd..b7117603cd 100644
--- a/lib/init-action.js
+++ b/lib/init-action.js
@@ -105521,6 +105521,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/resolve-environment-action.js b/lib/resolve-environment-action.js
index fe419d9104..90f7271554 100644
--- a/lib/resolve-environment-action.js
+++ b/lib/resolve-environment-action.js
@@ -104266,6 +104266,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/setup-codeql-action.js b/lib/setup-codeql-action.js
index e9a5e8dce8..12e7c4d74c 100644
--- a/lib/setup-codeql-action.js
+++ b/lib/setup-codeql-action.js
@@ -104163,6 +104163,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/start-proxy-action-post.js b/lib/start-proxy-action-post.js
index 14fa9fd053..6666bff38a 100644
--- a/lib/start-proxy-action-post.js
+++ b/lib/start-proxy-action-post.js
@@ -161632,6 +161632,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/start-proxy-action.js b/lib/start-proxy-action.js
index 13996a08fe..e238dd691f 100644
--- a/lib/start-proxy-action.js
+++ b/lib/start-proxy-action.js
@@ -120955,6 +120955,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
@@ -121747,6 +121752,16 @@ var LANGUAGE_TO_REGISTRY_TYPE = {
   rust: ["cargo_registry"],
   go: ["goproxy_server", "git_source"]
 };
+var NEW_LANGUAGE_TO_REGISTRY_TYPE = {
+  actions: [],
+  java: ["maven_repository"],
+  csharp: ["nuget_feed"],
+  javascript: [],
+  python: [],
+  ruby: [],
+  rust: [],
+  go: ["goproxy_server", "git_source"]
+};
 function getRegistryAddress(registry) {
   if (isDefined2(registry.url)) {
     return {
@@ -121764,8 +121779,9 @@ function getRegistryAddress(registry) {
     );
   }
 }
-function getCredentials(logger, registrySecrets, registriesCredentials, language) {
-  const registryTypeForLanguage = language ? LANGUAGE_TO_REGISTRY_TYPE[language] : void 0;
+function getCredentials(logger, registrySecrets, registriesCredentials, language, skipUnusedRegistries = false) {
+  const registryMapping = skipUnusedRegistries ? NEW_LANGUAGE_TO_REGISTRY_TYPE : LANGUAGE_TO_REGISTRY_TYPE;
+  const registryTypeForLanguage = language ? registryMapping[language] : void 0;
   let credentialsStr;
   if (registriesCredentials !== void 0) {
     logger.info(`Using registries_credentials input.`);
@@ -122262,11 +122278,15 @@ async function run(startedAt) {
     );
     const languageInput = getOptionalInput("language");
     language = languageInput ? parseLanguage(languageInput) : void 0;
+    const skipUnusedRegistries = await features.getValue(
+      "start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */
+    );
     const credentials = getCredentials(
       logger,
       getOptionalInput("registry_secrets"),
       getOptionalInput("registries_credentials"),
-      language
+      language,
+      skipUnusedRegistries
     );
     if (credentials.length === 0) {
       logger.info("No credentials found, skipping proxy setup.");
diff --git a/lib/upload-lib.js b/lib/upload-lib.js
index eadfa50638..75d7e6f260 100644
--- a/lib/upload-lib.js
+++ b/lib/upload-lib.js
@@ -107434,6 +107434,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/upload-sarif-action-post.js b/lib/upload-sarif-action-post.js
index 103b279d16..167786e844 100644
--- a/lib/upload-sarif-action-post.js
+++ b/lib/upload-sarif-action-post.js
@@ -161794,6 +161794,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/lib/upload-sarif-action.js b/lib/upload-sarif-action.js
index 91ddb60d51..02c7c0d6ca 100644
--- a/lib/upload-sarif-action.js
+++ b/lib/upload-sarif-action.js
@@ -107147,6 +107147,11 @@ var featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: void 0
   },
+  ["start_proxy_remove_unused_registries" /* StartProxyRemoveUnusedRegistries */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: void 0
+  },
   ["start_proxy_use_features_release" /* StartProxyUseFeaturesRelease */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/src/feature-flags.ts b/src/feature-flags.ts
index 546d2e0ff8..f061790e8a 100644
--- a/src/feature-flags.ts
+++ b/src/feature-flags.ts
@@ -77,6 +77,7 @@ export enum Feature {
   QaTelemetryEnabled = "qa_telemetry_enabled",
   /** Note that this currently only disables baseline file coverage information. */
   SkipFileCoverageOnPrs = "skip_file_coverage_on_prs",
+  StartProxyRemoveUnusedRegistries = "start_proxy_remove_unused_registries",
   StartProxyUseFeaturesRelease = "start_proxy_use_features_release",
   UploadOverlayDbToApi = "upload_overlay_db_to_api",
   UseRepositoryProperties = "use_repository_properties_v2",
@@ -328,6 +329,11 @@ export const featureConfig = {
     // cannot be found when interpreting results.
     minimumVersion: undefined,
   },
+  [Feature.StartProxyRemoveUnusedRegistries]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_START_PROXY_REMOVE_UNUSED_REGISTRIES",
+    minimumVersion: undefined,
+  },
   [Feature.StartProxyUseFeaturesRelease]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_START_PROXY_USE_FEATURES_RELEASE",
diff --git a/src/start-proxy-action.ts b/src/start-proxy-action.ts
index 438d565ae8..29c76643e3 100644
--- a/src/start-proxy-action.ts
+++ b/src/start-proxy-action.ts
@@ -5,7 +5,7 @@ import * as core from "@actions/core";
 
 import * as actionsUtil from "./actions-util";
 import { getGitHubVersion } from "./api-client";
-import { FeatureEnablement, initFeatures } from "./feature-flags";
+import { Feature, FeatureEnablement, initFeatures } from "./feature-flags";
 import { KnownLanguage } from "./languages";
 import { getActionsLogger, Logger } from "./logging";
 import { getRepositoryNwo } from "./repository";
@@ -58,12 +58,18 @@ async function run(startedAt: Date) {
     const languageInput = actionsUtil.getOptionalInput("language");
     language = languageInput ? parseLanguage(languageInput) : undefined;
 
+    // Query the FF for whether we should use the reduced registry mapping.
+    const skipUnusedRegistries = await features.getValue(
+      Feature.StartProxyRemoveUnusedRegistries,
+    );
+
     // Get the registry configurations from one of the inputs.
     const credentials = getCredentials(
       logger,
       actionsUtil.getOptionalInput("registry_secrets"),
       actionsUtil.getOptionalInput("registries_credentials"),
       language,
+      skipUnusedRegistries,
     );
 
     if (credentials.length === 0) {
diff --git a/src/start-proxy.test.ts b/src/start-proxy.test.ts
index b1c4926f8a..52456fe427 100644
--- a/src/start-proxy.test.ts
+++ b/src/start-proxy.test.ts
@@ -328,6 +328,32 @@ test("getCredentials logs a warning when a PAT is used without a username", asyn
   ]);
 });
 
+test("getCredentials returns all credentials for Actions when using LANGUAGE_TO_REGISTRY_TYPE", async (t) => {
+  const credentialsInput = toEncodedJSON(mixedCredentials);
+
+  const credentials = startProxyExports.getCredentials(
+    getRunnerLogger(true),
+    undefined,
+    credentialsInput,
+    KnownLanguage.actions,
+    false,
+  );
+  t.is(credentials.length, mixedCredentials.length);
+});
+
+test("getCredentials returns no credentials for Actions when using NEW_LANGUAGE_TO_REGISTRY_TYPE", async (t) => {
+  const credentialsInput = toEncodedJSON(mixedCredentials);
+
+  const credentials = startProxyExports.getCredentials(
+    getRunnerLogger(true),
+    undefined,
+    credentialsInput,
+    KnownLanguage.actions,
+    true,
+  );
+  t.deepEqual(credentials, []);
+});
+
 test("parseLanguage", async (t) => {
   // Exact matches
   t.deepEqual(parseLanguage("csharp"), KnownLanguage.csharp);
diff --git a/src/start-proxy.ts b/src/start-proxy.ts
index 7ed466a413..5aefa7bdfb 100644
--- a/src/start-proxy.ts
+++ b/src/start-proxy.ts
@@ -224,7 +224,9 @@ function isPAT(value: string) {
   ]);
 }
 
-const LANGUAGE_TO_REGISTRY_TYPE: Partial<Record<KnownLanguage, string[]>> = {
+type RegistryMapping = Partial<Record<KnownLanguage, string[]>>;
+
+const LANGUAGE_TO_REGISTRY_TYPE: RegistryMapping = {
   java: ["maven_repository"],
   csharp: ["nuget_feed"],
   javascript: ["npm_registry"],
@@ -234,6 +236,17 @@ const LANGUAGE_TO_REGISTRY_TYPE: Partial<Record<KnownLanguage, string[]>> = {
   go: ["goproxy_server", "git_source"],
 } as const;
 
+const NEW_LANGUAGE_TO_REGISTRY_TYPE: RegistryMapping = {
+  actions: [],
+  java: ["maven_repository"],
+  csharp: ["nuget_feed"],
+  javascript: [],
+  python: [],
+  ruby: [],
+  rust: [],
+  go: ["goproxy_server", "git_source"],
+} as const;
+
 /**
  * Extracts an `Address` value from the given `Registry` value by determining whether it has
  * a `url` value, or no `url` value but a `host` value.
@@ -267,9 +280,13 @@ export function getCredentials(
   registrySecrets: string | undefined,
   registriesCredentials: string | undefined,
   language: KnownLanguage | undefined,
+  skipUnusedRegistries: boolean = false,
 ): Credential[] {
+  const registryMapping = skipUnusedRegistries
+    ? NEW_LANGUAGE_TO_REGISTRY_TYPE
+    : LANGUAGE_TO_REGISTRY_TYPE;
   const registryTypeForLanguage = language
-    ? LANGUAGE_TO_REGISTRY_TYPE[language]
+    ? registryMapping[language]
     : undefined;
 
   let credentialsStr: string;