diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 6d314f66..68ce5ca4 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -259,3 +259,7 @@ jobs:
           GH_TOKEN: ${{ github.token }}
         run: |
           ./src/scripts/release/add_pr_comments_on_release.sh
+
+      - name: Send Slack notifications about release
+        run: |
+          python ./src/scripts/release/slack_notification.py '${{ secrets.SLACK_WEBHOOK_URL}}'
diff --git a/src/scripts/release/slack_notification.py b/src/scripts/release/slack_notification.py
new file mode 100644
index 00000000..ed257a28
--- /dev/null
+++ b/src/scripts/release/slack_notification.py
@@ -0,0 +1,26 @@
+import argparse
+
+import requests
+
+from olmo_core.version import VERSION
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        "slack-notifier", description="Send a release notifcation to a Slack channel."
+    )
+    parser.add_argument("webhook_url", type=str, help="The webhook URL for a Slack channel.")
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+    text = (
+        f"OLMo-core *v{VERSION}* is now out. See "
+        f"https://github.com/allenai/OLMo-core/releases/tag/v{VERSION} for release notes."
+    )
+    requests.post(args.webhook_url, json={"text": text})
+
+
+if __name__ == "__main__":
+    main()