diff --git a/.github/workflows/cloud-deploy-relay-staging.yml b/.github/workflows/cloud-deploy-relay-staging.yml
index 4e74c835100..93ef7acd264 100644
--- a/.github/workflows/cloud-deploy-relay-staging.yml
+++ b/.github/workflows/cloud-deploy-relay-staging.yml
@@ -74,6 +74,8 @@ jobs:
       IMAGE_NAME: relay
       EXPECTED_IMAGE_DIGEST: ${{ inputs.expected-image-digest }}
       CAPACITY_SERVICE_ACCOUNT: ${{ vars.STAGING_GCP_RELAY_CAPACITY_SERVICE_ACCOUNT }}
+      # The director must trust the identity every staging Relay workflow authenticates as.
+      DEPLOY_SERVICE_ACCOUNT: ${{ vars.STAGING_GCP_RELAY_DEPLOY_SERVICE_ACCOUNT }}
       ASIA_PROOF_SERVICE_ACCOUNT: ${{ vars.STAGING_GCP_RELAY_ASIA_PROOF_SERVICE_ACCOUNT }}
       REGIONAL_PLACEMENT_SECRET: orca-cloud-relay-regional-placement-enabled
       DIRECTOR_RUNTIME_SERVICE_ACCOUNT: orca-cloud-staging-relay-dir@onorca-cloud-staging.iam.gserviceaccount.com
@@ -199,6 +201,7 @@ jobs:
             --role director \
             --max-instances 2 \
             --capacity-service-account "${CAPACITY_SERVICE_ACCOUNT}" \
+            --deploy-service-account "${DEPLOY_SERVICE_ACCOUNT}" \
             --asia-proof-service-account "${ASIA_PROOF_SERVICE_ACCOUNT}" \
             --regional-placement-secret-version "${regional_version}" \
             "${floor_args[@]}" \
diff --git a/cloud/dev/scripts/deploy-relay-blue-green.mjs b/cloud/dev/scripts/deploy-relay-blue-green.mjs
index 72bb6355986..d93b2617e86 100644
--- a/cloud/dev/scripts/deploy-relay-blue-green.mjs
+++ b/cloud/dev/scripts/deploy-relay-blue-green.mjs
@@ -263,6 +263,7 @@ export function directorDeploymentEnvironment(config) {
   }
   const serviceAccount = projectServiceAccount(config, 'capacity-service-account')
   const asiaProofServiceAccount = projectServiceAccount(config, 'asia-proof-service-account')
+  const deployServiceAccount = projectServiceAccount(config, 'deploy-service-account')
   const rehomeDirectorServiceAccount = projectServiceAccount(
     config,
     'rehome-director-service-account'
@@ -274,6 +275,10 @@ export function directorDeploymentEnvironment(config) {
   if (asiaProofServiceAccount !== undefined) {
     environment.ORCA_RELAY_ASIA_PROOF_SERVICE_ACCOUNT = asiaProofServiceAccount
   }
+  // The admin identity the director trusts; omitted, the serving revision's value carries over.
+  if (deployServiceAccount !== undefined) {
+    environment.ORCA_RELAY_DEPLOY_SERVICE_ACCOUNT = deployServiceAccount
+  }
   if (rehomeDirectorServiceAccount !== undefined) {
     environment[DIRECTOR_REHOME_IDENTITY_ENV] = rehomeDirectorServiceAccount
     environment[DIRECTOR_REHOME_AUDIENCE_ENV] = config['rehome-audience']
@@ -330,6 +335,7 @@ export function parseArguments(argv) {
     }
     if (
       values['capacity-service-account'] !== undefined ||
+      values['deploy-service-account'] !== undefined ||
       values['director-cells-json'] !== undefined ||
       values['runtime-service-account'] !== undefined ||
       values['rehome-director-service-account'] !== undefined ||
diff --git a/cloud/dev/scripts/deploy-relay-blue-green.test.mjs b/cloud/dev/scripts/deploy-relay-blue-green.test.mjs
index 782ace852c7..4ab531b58a7 100644
--- a/cloud/dev/scripts/deploy-relay-blue-green.test.mjs
+++ b/cloud/dev/scripts/deploy-relay-blue-green.test.mjs
@@ -1023,6 +1023,30 @@ test('reads a director placement from runtime-status, and reports an image witho
   }
 })
 
+// Why: staging drifted to a director that trusts gha-deploy while every staging workflow
+// authenticates as gha-relay; the deploy, not Terraform, owns the live value.
+test('a director deploy sets the trusted deploy identity only when asked', () => {
+  const config = { project: 'onorca-cloud-staging' }
+  const relay = 'orca-cloud-staging-gha-relay@onorca-cloud-staging.iam.gserviceaccount.com'
+  assert.equal(
+    directorDeploymentEnvironment({ ...config, 'deploy-service-account': relay })
+      .ORCA_RELAY_DEPLOY_SERVICE_ACCOUNT,
+    relay
+  )
+  assert.equal(
+    'ORCA_RELAY_DEPLOY_SERVICE_ACCOUNT' in directorDeploymentEnvironment(config),
+    false
+  )
+  assert.throws(
+    () =>
+      directorDeploymentEnvironment({
+        ...config,
+        'deploy-service-account': 'foreign@other-project.iam.gserviceaccount.com'
+      }),
+    /selected project/
+  )
+})
+
 // Staging's director trusted gha-deploy while the workflow authenticated as gha-relay: a bare 401.
 test('the guard names the deploy identity a drifted director trusts instead of reading into a 401', async () => {
   const servingImageDigest = `sha256:${'f'.repeat(64)}`
diff --git a/cloud/dev/scripts/relay-staging-deploy-identity.test.mjs b/cloud/dev/scripts/relay-staging-deploy-identity.test.mjs
index 8b7fb069915..dbb3f1d7a14 100644
--- a/cloud/dev/scripts/relay-staging-deploy-identity.test.mjs
+++ b/cloud/dev/scripts/relay-staging-deploy-identity.test.mjs
@@ -232,4 +232,5 @@ test('the staging director deploy runs as relay-dir with its rehome identity', (
   assert.match(block, /--runtime-service-account "\$\{DIRECTOR_RUNTIME_SERVICE_ACCOUNT\}"/)
   assert.match(block, /--rehome-director-service-account "\$\{DIRECTOR_RUNTIME_SERVICE_ACCOUNT\}"/)
   assert.match(source, /DIRECTOR_RUNTIME_SERVICE_ACCOUNT: orca-cloud-staging-relay-dir@/)
+  assert.match(block, /--deploy-service-account "\$\{DEPLOY_SERVICE_ACCOUNT\}"/)
 })