diff --git a/.changeset/rich-mayflies-do.md b/.changeset/rich-mayflies-do.md
new file mode 100644
index 0000000000..d68e00c0aa
--- /dev/null
+++ b/.changeset/rich-mayflies-do.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-kubernetes-backend': patch
+---
+
+Fixes bug reading ExternalId from k8s backend config
diff --git a/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.test.ts b/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.test.ts
index 1642ca5580..dac96e4cef 100644
--- a/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.test.ts
+++ b/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.test.ts
@@ -115,6 +115,14 @@ describe('ConfigClusterLocator', () => {
           authProvider: 'aws',
           skipTLSVerify: true,
         },
+        {
+          assumeRole: 'SomeRole',
+          name: 'cluster2',
+          externalId: 'SomeExternalId',
+          url: 'http://localhost:8081',
+          authProvider: 'aws',
+          skipTLSVerify: true,
+        },
       ],
     });
 
@@ -127,6 +135,7 @@ describe('ConfigClusterLocator', () => {
         assumeRole: undefined,
         name: 'cluster1',
         serviceAccountToken: 'token',
+        externalId: undefined,
         url: 'http://localhost:8080',
         authProvider: 'aws',
         skipTLSVerify: false,
@@ -134,11 +143,21 @@ describe('ConfigClusterLocator', () => {
       {
         assumeRole: 'SomeRole',
         name: 'cluster2',
+        externalId: undefined,
         serviceAccountToken: undefined,
         url: 'http://localhost:8081',
         authProvider: 'aws',
         skipTLSVerify: true,
       },
+      {
+        assumeRole: 'SomeRole',
+        name: 'cluster2',
+        externalId: 'SomeExternalId',
+        url: 'http://localhost:8081',
+        serviceAccountToken: undefined,
+        authProvider: 'aws',
+        skipTLSVerify: true,
+      },
     ]);
   });
 });
diff --git a/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.ts b/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.ts
index 2899445b2a..8352db6754 100644
--- a/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.ts
+++ b/plugins/kubernetes-backend/src/cluster-locator/ConfigClusterLocator.ts
@@ -44,7 +44,9 @@ export class ConfigClusterLocator implements KubernetesClustersSupplier {
           }
           case 'aws': {
             const assumeRole = c.getOptionalString('assumeRole');
-            return { assumeRole, ...clusterDetails };
+            const externalId = c.getOptionalString('externalId');
+
+            return { assumeRole, externalId, ...clusterDetails };
           }
           case 'serviceAccount': {
             return clusterDetails;