diff --git a/.github/scripts/close-xls-discussions.py b/.github/scripts/close-xls-discussions.py
new file mode 100644
index 00000000..5ca635c3
--- /dev/null
+++ b/.github/scripts/close-xls-discussions.py
@@ -0,0 +1,272 @@
+#!/usr/bin/env python3
+"""
+Close XLS Discussions - Closes and locks discussions linked in proposal-from fields.
+
+This script is designed to run as part of a GitHub Action after an XLS is merged
+into master, or manually via workflow_dispatch to scan all XLS folders.
+"""
+
+import json
+import os
+import re
+import subprocess
+import sys
+from pathlib import Path
+
+# Add scripts directory to path for xls_parser import
+sys.path.insert(0, str(Path(__file__).parent.parent.parent / "scripts"))
+
+from xls_parser import extract_xls_metadata, find_xls_documents
+
+
+def run_gh_command(args: list[str], check: bool = True) -> subprocess.CompletedProcess:
+    """Run a GitHub CLI command."""
+    result = subprocess.run(["gh"] + args, capture_output=True, text=True, check=False)
+    if check and result.returncode != 0:
+        print(f"Error running gh command: {' '.join(args)}")
+        print(f"stderr: {result.stderr}")
+        raise subprocess.CalledProcessError(
+            result.returncode, args, result.stdout, result.stderr
+        )
+    return result
+
+
+def run_graphql_query(query: str, variables: dict) -> dict:
+    """Run a GraphQL query using the GitHub CLI."""
+    args = ["api", "graphql", "-f", f"query={query}"]
+    for key, value in variables.items():
+        args.extend(["-f", f"{key}={value}"])
+
+    result = run_gh_command(args)
+    return json.loads(result.stdout)
+
+
+def extract_discussion_number(url: str) -> int | None:
+    """Extract discussion number from a GitHub discussions URL."""
+    # Match URLs like https://github.com/XRPLF/XRPL-Standards/discussions/123
+    match = re.search(r"/discussions/(\d+)", url)
+    if match:
+        return int(match.group(1))
+    return None
+
+
+def get_discussion_info(owner: str, repo: str, number: int) -> dict | None:
+    """Get discussion info by number."""
+    query = """
+    query($owner: String!, $repo: String!, $number: Int!) {
+      repository(owner: $owner, name: $repo) {
+        discussion(number: $number) {
+          id
+          title
+          closed
+          locked
+          url
+        }
+      }
+    }
+    """
+    try:
+        result = run_graphql_query(
+            query, {"owner": owner, "repo": repo, "number": str(number)}
+        )
+        return result.get("data", {}).get("repository", {}).get("discussion")
+    except subprocess.CalledProcessError:
+        return None
+
+
+def close_and_lock_discussion(
+    discussion_id: str,
+    close_message: str,
+    xls_folder: str,
+    dry_run: bool = False,
+) -> bool:
+    """Close and lock a discussion with a comment."""
+    # Customize message with XLS reference
+    message = f"{close_message}\n\nSee: [{xls_folder}](/{xls_folder}/README.md)"
+
+    if dry_run:
+        print("  [DRY RUN] Would add comment, close, and lock discussion")
+        return True
+
+    # Add comment
+    print("  Adding close comment...")
+    comment_query = """
+    mutation($discussionId: ID!, $body: String!) {
+      addDiscussionComment(input: {discussionId: $discussionId, body: $body}) {
+        comment { id }
+      }
+    }
+    """
+    try:
+        run_graphql_query(
+            comment_query, {"discussionId": discussion_id, "body": message}
+        )
+    except subprocess.CalledProcessError as e:
+        print(f"  Error adding comment: {e}")
+        return False
+
+    # Close discussion
+    print("  Closing discussion...")
+    close_query = """
+    mutation($discussionId: ID!) {
+      closeDiscussion(input: {discussionId: $discussionId}) {
+        discussion { id }
+      }
+    }
+    """
+    try:
+        run_graphql_query(close_query, {"discussionId": discussion_id})
+    except subprocess.CalledProcessError as e:
+        print(f"  Error closing discussion: {e}")
+        return False
+
+    # Lock discussion
+    print("  Locking discussion...")
+    lock_query = """
+    mutation($discussionId: ID!) {
+      lockLockable(input: {lockableId: $discussionId}) {
+        lockedRecord { locked }
+      }
+    }
+    """
+    try:
+        run_graphql_query(lock_query, {"discussionId": discussion_id})
+    except subprocess.CalledProcessError as e:
+        print(f"  Warning: Failed to lock discussion: {e}")
+        # Don't return False - closing succeeded
+
+    return True
+
+
+def get_xls_folders_from_changed_files(changed_files: str) -> list[str]:
+    """Extract XLS folder names from a space-separated list of changed files."""
+    if not changed_files:
+        return []
+
+    xls_folders = set()
+    for file_path in changed_files.split():
+        # Match XLS-*/README.md
+        match = re.match(r"(XLS-\d+[d]?)/README\.md", file_path)
+        if match:
+            xls_folders.add(match.group(1))
+
+    return list(xls_folders)
+
+
+def main():
+    """Main entry point."""
+    # Get environment variables
+    owner = os.environ.get("GITHUB_REPOSITORY_OWNER", "")
+    repo = os.environ.get("GITHUB_REPOSITORY_NAME", "")
+    close_message = os.environ.get(
+        "CLOSE_MESSAGE", "This discussion has been merged into an XLS."
+    )
+    scan_all = os.environ.get("SCAN_ALL", "false").lower() == "true"
+    dry_run = os.environ.get("DRY_RUN", "false").lower() == "true"
+    changed_files = os.environ.get("CHANGED_FILES", "")
+
+    if not owner or not repo:
+        print(
+            "Error: GITHUB_REPOSITORY_OWNER and " "GITHUB_REPOSITORY_NAME must be set"
+        )
+        sys.exit(1)
+
+    print(f"Repository: {owner}/{repo}")
+    print(f"Scan all: {scan_all}")
+    print(f"Dry run: {dry_run}")
+    print()
+
+    root_dir = Path(".")
+
+    # Determine which XLS folders to process
+    if scan_all:
+        print("Scanning all XLS folders...")
+        docs = find_xls_documents(root_dir)
+    else:
+        print("Scanning changed XLS folders...")
+        changed_folders = get_xls_folders_from_changed_files(changed_files)
+        print(f"Changed folders: {changed_folders}")
+
+        if not changed_folders:
+            print("No XLS folders changed. Nothing to do.")
+            return
+
+        docs = []
+        for folder_name in changed_folders:
+            readme_path = root_dir / folder_name / "README.md"
+            if readme_path.exists():
+                with open(readme_path, "r", encoding="utf-8") as f:
+                    content = f.read()
+                doc = extract_xls_metadata(content, folder_name)
+                if doc:
+                    docs.append(doc)
+
+    if not docs:
+        print("No XLS documents found.")
+        return
+
+    print(f"\nFound {len(docs)} XLS document(s) to process")
+    print()
+
+    # Process each document
+    closed_count = 0
+    skipped_count = 0
+    error_count = 0
+
+    for doc in docs:
+        if not doc.proposal_from:
+            print(f"{doc.folder}: No proposal-from field, skipping")
+            skipped_count += 1
+            continue
+
+        discussion_number = extract_discussion_number(doc.proposal_from)
+        if not discussion_number:
+            print(
+                f"{doc.folder}: Could not extract discussion number "
+                f"from '{doc.proposal_from}', skipping"
+            )
+            skipped_count += 1
+            continue
+
+        print(f"{doc.folder}: Processing discussion #{discussion_number}")
+
+        # Get discussion info
+        discussion = get_discussion_info(owner, repo, discussion_number)
+        if not discussion:
+            print(f"  Warning: Could not find discussion #{discussion_number}")
+            error_count += 1
+            continue
+
+        print(f"  Title: {discussion['title']}")
+        print(f"  URL: {discussion['url']}")
+
+        if discussion["closed"]:
+            print("  Already closed, skipping")
+            skipped_count += 1
+            continue
+
+        # Close and lock
+        if close_and_lock_discussion(
+            discussion["id"], close_message, doc.folder, dry_run=dry_run
+        ):
+            print("  ✓ Successfully closed and locked")
+            closed_count += 1
+        else:
+            print("  ✗ Failed to close/lock")
+            error_count += 1
+
+        print()
+
+    # Summary
+    print("=" * 50)
+    print("Summary:")
+    print(f"  Closed: {closed_count}")
+    print(f"  Skipped: {skipped_count}")
+    print(f"  Errors: {error_count}")
+
+    if error_count > 0:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/.github/workflows/close-xls-discussions.yml b/.github/workflows/close-xls-discussions.yml
new file mode 100644
index 00000000..52e19578
--- /dev/null
+++ b/.github/workflows/close-xls-discussions.yml
@@ -0,0 +1,75 @@
+name: Close XLS Discussions
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - "XLS-*/README.md"
+  workflow_dispatch:
+    inputs:
+      scan_all:
+        description: "Scan all XLS folders (not just changed files)"
+        required: false
+        default: true
+        type: boolean
+      dry_run:
+        description: "Dry run mode (no actual changes)"
+        required: false
+        default: false
+        type: boolean
+
+permissions:
+  discussions: write
+  contents: read
+
+env:
+  CLOSE_MESSAGE: |
+    This discussion has been merged into an XLS and is now being closed.
+
+    Thank you for your contribution to the XRP Ledger Standards process!
+
+jobs:
+  close-discussions:
+    runs-on: ubuntu-latest
+    if: github.repository == 'XRPLF/XRPL-Standards'
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v6
+
+      - name: Get changed XLS files
+        id: changed-files
+        if: github.event_name == 'push'
+        uses: tj-actions/changed-files@v47
+        with:
+          files: |
+            XLS-*/README.md
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install dependencies
+        run: |
+          pip install beautifulsoup4
+
+      - name: Generate token from GitHub App
+        id: generate_token
+        uses: actions/create-github-app-token@v2
+        with:
+          app-id: ${{ secrets.APP_ID }}
+          private-key: ${{ secrets.APP_PRIVATE_KEY }}
+
+      - name: Close merged XLS discussions
+        env:
+          GH_TOKEN: ${{ steps.generate_token.outputs.token }}
+          GITHUB_REPOSITORY_OWNER: ${{ github.repository_owner }}
+          GITHUB_REPOSITORY_NAME: ${{ github.event.repository.name }}
+          CLOSE_MESSAGE: ${{ env.CLOSE_MESSAGE }}
+          SCAN_ALL: ${{ github.event_name == 'workflow_dispatch' && inputs.scan_all || 'false' }}
+          DRY_RUN: ${{ github.event_name == 'workflow_dispatch' && inputs.dry_run || 'false' }}
+          CHANGED_FILES: ${{ steps.changed-files.outputs.all_changed_files }}
+        run: |
+          python .github/scripts/close-xls-discussions.py