diff --git a/.github/workflows/deploy-queue-watchdog.yml b/.github/workflows/deploy-queue-watchdog.yml
new file mode 100644
index 00000000..a7670cf2
--- /dev/null
+++ b/.github/workflows/deploy-queue-watchdog.yml
@@ -0,0 +1,91 @@
+name: deploy-queue-watchdog
+
+# Alerts when a deploy or rollback run has sat in `queued` or `pending` for
+# hours, or in `waiting` for most of a day. The per-cloud deploy jobs share a
+# job-level concurrency group
+# (`<cloud>-tfstate-<env>`, cancel-in-progress: false), so one run that never
+# starts holds the slot and every later deploy or rollback waits behind it
+# (issue #708: GCP and Azure dev deploys frozen from 2026-10-05).
+#
+# Alert-only on purpose: the job fails (red scheduled run, GitHub notifies) and
+# lists the stuck runs; a human cancels them. `waiting` is how the AWS dev
+# orphan in #708 showed up (no approval gate on dev), but it is also the state
+# of a run awaiting a required environment approval, so it only alerts after
+# 720 minutes and is labeled "approval or orphaned". The `test` job runs the
+# script's self-test when the script or this workflow changes.
+
+on:
+  schedule:
+    - cron: "17,47 * * * *"
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - ".github/workflows/deploy-queue-watchdog.yml"
+      - "scripts/check-stuck-deploy-runs.sh"
+      - "scripts/test-check-stuck-deploy-runs.sh"
+
+permissions:
+  contents: read
+
+concurrency:
+  group: deploy-queue-watchdog-${{ github.event_name }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    name: Watchdog script self-test
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
+
+      - name: Run self-test
+        run: bash scripts/test-check-stuck-deploy-runs.sh
+
+  watch:
+    name: Look for stuck deploy runs
+    if: github.event_name != 'pull_request'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      contents: read
+      actions: read
+    env:
+      GH_TOKEN: ${{ github.token }}
+      GH_REPO: ${{ github.repository }}
+      STUCK_AFTER_MINUTES: "120"
+      WAITING_AFTER_MINUTES: "720"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
+
+      - name: Collect queued, pending and waiting runs of the deploy workflows
+        run: |
+          set -euo pipefail
+          : > runs.jsonl
+          for wf in deploy-gcp.yml deploy-azure.yml deploy-aws-lambda.yml deploy-aws-fargate.yml deploy-all.yml rollback.yml; do
+            for status in queued pending waiting; do
+              gh run list --workflow "$wf" --status "$status" --limit 50 \
+                --json databaseId,workflowName,status,createdAt,url,headBranch >> runs.jsonl
+            done
+          done
+          jq -s 'add // []' runs.jsonl > runs.json
+
+      - name: Fail on stuck runs
+        run: |
+          set -euo pipefail
+          status=0
+          bash scripts/check-stuck-deploy-runs.sh < runs.json | tee report.txt || status=$?
+          {
+            echo '### Deploy queue watchdog'
+            echo '```'
+            cat report.txt
+            echo '```'
+          } >> "$GITHUB_STEP_SUMMARY"
+          exit "$status"
diff --git a/scripts/check-stuck-deploy-runs.sh b/scripts/check-stuck-deploy-runs.sh
new file mode 100644
index 00000000..5d3226d0
--- /dev/null
+++ b/scripts/check-stuck-deploy-runs.sh
@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+# check-stuck-deploy-runs.sh
+#
+# Reads a JSON array of workflow runs on stdin (the output of
+# `gh run list --json databaseId,workflowName,status,createdAt,url,headBranch`)
+# and reports runs that have been queued or pending for STUCK_AFTER_MINUTES
+# (default 120) or longer, and runs that have been waiting for
+# WAITING_AFTER_MINUTES (default 720) or longer.
+#
+# Why: a deploy run stuck in `queued` holds the job-level concurrency group
+# (`<cloud>-tfstate-<env>`, cancel-in-progress: false) and every later deploy
+# or rollback waits behind it (issue #708). `waiting` is how an orphaned
+# holder looked on AWS dev (no approval gate there), but it is also the state
+# of a run legitimately waiting for a required environment approval, so it gets
+# a much longer threshold and its own label.
+#
+# Exit codes: 0 nothing stuck, 1 at least one stuck run, 2 bad input.
+# NOW_EPOCH overrides the clock (used by the self-test).
+
+set -euo pipefail
+
+threshold_minutes="${STUCK_AFTER_MINUTES:-120}"
+waiting_minutes="${WAITING_AFTER_MINUTES:-720}"
+now_epoch="${NOW_EPOCH:-$(date -u +%s)}"
+
+for pair in "STUCK_AFTER_MINUTES=$threshold_minutes" "WAITING_AFTER_MINUTES=$waiting_minutes"; do
+  if ! [[ "${pair#*=}" =~ ^[0-9]+$ ]]; then
+    echo "${pair%%=*} must be a non-negative integer, got '${pair#*=}'" >&2
+    exit 2
+  fi
+done
+
+stuck="$(jq -r --argjson now "$now_epoch" --argjson limit "$threshold_minutes" --argjson wlimit "$waiting_minutes" '
+  map(select(.status == "queued" or .status == "pending" or .status == "waiting"))
+  | map(. + {age_min: (($now - (.createdAt | fromdateiso8601)) / 60 | floor)})
+  | map(select(.age_min >= (if .status == "waiting" then $wlimit else $limit end)))
+  | sort_by(.createdAt)
+  | .[]
+  | (if .status == "waiting" then "waiting (approval or orphaned)" else .status end) as $label
+  | "\(.workflowName) run \(.databaseId) (\(.headBranch)) has been \($label) for \(.age_min) min: \(.url)"
+' 2>/dev/null)" || {
+  echo "input is not a JSON array of runs" >&2
+  exit 2
+}
+
+if [[ -z "$stuck" ]]; then
+  echo "No deploy run has been queued or pending for ${threshold_minutes} min or more, or waiting for ${waiting_minutes} min or more."
+  exit 0
+fi
+
+echo "$stuck"
+echo
+echo "Stuck runs hold the deploy concurrency group and block later deploys and rollbacks."
+echo "A waiting run may just be awaiting an environment approval; check the run page before cancelling."
+echo "Cancel them with: gh run cancel <run-id> --repo \"\$GITHUB_REPOSITORY\", then re-run the latest deploy."
+exit 1
diff --git a/scripts/test-check-stuck-deploy-runs.sh b/scripts/test-check-stuck-deploy-runs.sh
new file mode 100644
index 00000000..2b916c6a
--- /dev/null
+++ b/scripts/test-check-stuck-deploy-runs.sh
@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+# test-check-stuck-deploy-runs.sh
+#
+# Self-test for check-stuck-deploy-runs.sh. Fixed clock, fixture run lists.
+# Exits 0 when all cases pass; exits 1 on any failure.
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+CHECK="${SCRIPT_DIR}/check-stuck-deploy-runs.sh"
+
+# 2026-10-09T12:00:00Z
+NOW=1791547200
+
+pass=0
+fail=0
+
+run_case() {
+  local label="$1" expected_exit="$2" input="$3" expected_text="${4:-}"
+  local out actual_exit=0
+  out="$(printf '%s' "$input" | NOW_EPOCH="$NOW" bash "$CHECK" 2>&1)" || actual_exit=$?
+  if [[ "$actual_exit" -ne "$expected_exit" ]]; then
+    echo "FAIL: $label (expected exit $expected_exit, got $actual_exit)"
+    (( fail++ )) || true
+    return
+  fi
+  if [[ -n "$expected_text" && "$out" != *"$expected_text"* ]]; then
+    echo "FAIL: $label (output missing '$expected_text')"
+    (( fail++ )) || true
+    return
+  fi
+  echo "PASS: $label"
+  (( pass++ )) || true
+}
+
+run() { # id status createdAt
+  printf '{"databaseId":%s,"workflowName":"Deploy to GCP Cloud Run","status":"%s","createdAt":"%s","url":"https://example.invalid/runs/%s","headBranch":"main"}' "$1" "$2" "$3" "$1"
+}
+
+old="2026-10-09T08:00:00Z"   # 240 min before NOW
+fresh="2026-10-09T11:30:00Z" # 30 min before NOW
+edge="2026-10-09T10:00:00Z"  # exactly 120 min before NOW
+wedge="2026-10-09T00:00:00Z" # exactly 720 min before NOW
+wold="2026-10-08T23:00:00Z"  # 780 min before NOW
+
+run_case "empty list is clean" 0 "[]" "No deploy run"
+run_case "old queued run is stuck" 1 "[$(run 1 queued "$old")]" "run 1 (main) has been queued for 240 min"
+run_case "old pending run is stuck" 1 "[$(run 2 pending "$old")]" "has been pending"
+run_case "fresh queued run is fine" 0 "[$(run 3 queued "$fresh")]"
+run_case "run exactly at the threshold is stuck" 1 "[$(run 4 queued "$edge")]"
+run_case "waiting run under the waiting threshold is fine" 0 "[$(run 5 waiting "$old")]"
+run_case "waiting run past the waiting threshold is reported" 1 "[$(run 10 waiting "$wold")]" "waiting (approval or orphaned) for 780 min"
+run_case "waiting run exactly at the waiting threshold is reported" 1 "[$(run 11 waiting "$wedge")]"
+run_case "old in_progress run is ignored" 0 "[$(run 6 in_progress "$old")]"
+run_case "one stuck among fine runs is reported" 1 "[$(run 7 queued "$fresh"),$(run 8 queued "$old"),$(run 9 waiting "$old")]" "run 8"
+run_case "a waiting run does not use the short threshold" 0 "[$(run 12 waiting "$edge")]"
+run_case "not JSON is a bad-input error" 2 "this is not json"
+run_case "JSON object instead of array is a bad-input error" 2 '{"a":1}'
+
+out_exit=0
+STUCK_AFTER_MINUTES=abc bash "$CHECK" </dev/null >/dev/null 2>&1 || out_exit=$?
+if [[ "$out_exit" -eq 2 ]]; then echo "PASS: non-numeric threshold is rejected"; (( pass++ )) || true
+else echo "FAIL: non-numeric threshold (got exit $out_exit)"; (( fail++ )) || true; fi
+
+wexit=0
+WAITING_AFTER_MINUTES=-5 bash "$CHECK" </dev/null >/dev/null 2>&1 || wexit=$?
+if [[ "$wexit" -eq 2 ]]; then echo "PASS: invalid waiting threshold is rejected"; (( pass++ )) || true
+else echo "FAIL: invalid waiting threshold (got exit $wexit)"; (( fail++ )) || true; fi
+
+echo "$pass passed, $fail failed"
+[[ "$fail" -eq 0 ]]