diff --git a/.github/workflows/weekly-branch-promotions.yml b/.github/workflows/weekly-branch-promotions.yml
new file mode 100644
index 0000000..7b1a8c4
--- /dev/null
+++ b/.github/workflows/weekly-branch-promotions.yml
@@ -0,0 +1,69 @@
+name: 🔁 Weekly Branch Promotions
+
+on:
+  schedule:
+    - cron: "0 6 * * 1"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pull-requests: write
+
+concurrency:
+  group: weekly-branch-promotions
+  cancel-in-progress: false
+
+jobs:
+  open-promotion-pr:
+    name: Open ${{ matrix.head }} → ${{ matrix.base }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - head: develop
+            base: design
+            title: "chore: merge develop into design"
+          - head: design
+            base: main
+            title: "chore: merge design into main"
+
+    steps:
+      - name: ⬇️ Checkout
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: 🔁 Open promotion PR
+        env:
+          GH_TOKEN: ${{ github.token }}
+          BASE_BRANCH: ${{ matrix.base }}
+          HEAD_BRANCH: ${{ matrix.head }}
+          PR_TITLE: ${{ matrix.title }}
+        run: |
+          set -euo pipefail
+
+          git fetch origin "$BASE_BRANCH" "$HEAD_BRANCH"
+
+          if git merge-base --is-ancestor "origin/$HEAD_BRANCH" "origin/$BASE_BRANCH"; then
+            echo "No promotion needed: $BASE_BRANCH already contains $HEAD_BRANCH."
+            exit 0
+          fi
+
+          existing_pr="$(gh pr list \
+            --state open \
+            --base "$BASE_BRANCH" \
+            --head "$GITHUB_REPOSITORY_OWNER:$HEAD_BRANCH" \
+            --json number \
+            --jq '.[0].number // empty')"
+
+          if [ -n "$existing_pr" ]; then
+            echo "Promotion PR already open: #$existing_pr."
+            exit 0
+          fi
+
+          gh pr create \
+            --base "$BASE_BRANCH" \
+            --head "$HEAD_BRANCH" \
+            --title "$PR_TITLE" \
+            --body "Automated weekly promotion PR from \`$HEAD_BRANCH\` to \`$BASE_BRANCH\`."