diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2cae2b8e1..3e45f6620 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -100,7 +100,7 @@ jobs:
           # Warm the symfony cache so it gets bundled with phar.
           ./bin/acli
           composer box-compile
-      - name: Store artifact
+      - name: Store artifact in Actions
         uses: actions/upload-artifact@v4
         with:
           name: acli.phar
diff --git a/.github/workflows/upload-s3.yml b/.github/workflows/upload-s3.yml
new file mode 100644
index 000000000..33ed6b509
--- /dev/null
+++ b/.github/workflows/upload-s3.yml
@@ -0,0 +1,61 @@
+name: Upload phar to S3
+on:
+  workflow_run:
+    workflows: [CI]
+    types:
+      - completed
+jobs:
+  download:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Find associated pull request
+        id: pr
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+        with:
+          script: |
+            const response = await github.rest.search.issuesAndPullRequests({
+              q: 'repo:${{ github.repository }} is:pr sha:${{ github.event.workflow_run.head_sha }}',
+              per_page: 1,
+            })
+            const items = response.data.items
+            if (items.length < 1) {
+              console.error('No PRs found')
+              return
+            }
+            const pullRequestNumber = items[0].number
+            console.info("Pull request number is", pullRequestNumber)
+            return pullRequestNumber
+      - name: 'Download artifact'
+        uses: actions/github-script@v6
+        with:
+          script: |
+            let allArtifacts = await github.rest.actions.listWorkflowRunArtifacts({
+               owner: context.repo.owner,
+               repo: context.repo.repo,
+               run_id: context.payload.workflow_run.id,
+            });
+            let matchArtifact = allArtifacts.data.artifacts.filter((artifact) => {
+              return artifact.name == "acli.phar"
+            })[0];
+            let download = await github.rest.actions.downloadArtifact({
+               owner: context.repo.owner,
+               repo: context.repo.repo,
+               artifact_id: matchArtifact.id,
+               archive_format: 'zip',
+            });
+            let fs = require('fs');
+            fs.writeFileSync(`${process.env.GITHUB_WORKSPACE}/acli.phar.zip`, Buffer.from(download.data));
+      - name: 'Unzip artifact'
+        run: unzip acli.phar.zip
+      - name: Store artifact in S3
+        run: |
+          aws s3 cp acli.phar s3://acquia-cli/build/$GITHUB_SHA/
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          AWS_DEFAULT_REGION: us-east-1
+      - name: Comment on PR
+        run: 'gh pr comment --edit-last https://github.com/$GITHUB_REPOSITORY/pull/$GITHUB_PR --body "Try the dev build for this PR: https://acquia-cli.s3.amazonaws.com/builds/$GITHUB_SHA/acli.phar"'
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GITHUB_PR: ${{ steps.pr.outputs.result }}