diff --git a/scripts/README.md b/scripts/README.md
index 714430e..757798c 100644
--- a/scripts/README.md
+++ b/scripts/README.md
@@ -1,5 +1,9 @@
 # scripts
 
+## add-codeowners-to-repositories
+
+See: [add-codeowners-to-repositories](./add-codeowners-to-repositories/README.md)
+
 ## add-dependabot-file-to-repositories.js
 
 Add `dependabot.yml` file to a list of repositories.
diff --git a/scripts/add-codeowners-to-repositories/README.md b/scripts/add-codeowners-to-repositories/README.md
new file mode 100644
index 0000000..c4cc2c5
--- /dev/null
+++ b/scripts/add-codeowners-to-repositories/README.md
@@ -0,0 +1,93 @@
+# add-codeowners-to-repositories
+
+Adds a CODEOWNERS file to the default branch in a list of repositories.
+
+## Prerequisites
+
+- Node.js 18+
+- `GITHUB_TOKEN` environment variable with `repo` scope
+
+## Installation
+
+```bash
+npm install
+```
+
+## Options
+
+| Option | Description |
+|--------|-------------|
+| `--repos-file <file>` | File containing list of repositories (org/repo format, one per line) |
+| `--codeowners <file>` | Path to the CODEOWNERS file to add |
+| `--overwrite` | Overwrite existing CODEOWNERS file (default: append) |
+| `--create-pr` | Create a pull request instead of committing directly |
+| `--branch <name>` | Branch name for PR (default: `add-codeowners`) |
+| `--pr-title <title>` | PR title (default: `Add CODEOWNERS file`) |
+| `--dry-run` | Show what would be done without making changes |
+| `--concurrency <n>` | Number of concurrent API calls (default: 10) |
+| `--help` | Show help message |
+
+### Environment Variables
+
+| Variable | Description |
+|----------|-------------|
+| `GITHUB_TOKEN` | GitHub PAT with `repo` scope (required) |
+| `GITHUB_API_URL` | API endpoint (defaults to `https://api.github.com`) |
+
+## Input File Format
+
+The repos file should contain one repository per line in `org/repo` format:
+
+```
+my-org/repo-1
+my-org/repo-2
+other-org/repo-3
+```
+
+Lines starting with `#` are treated as comments and ignored. Empty lines are also ignored.
+
+## Behavior
+
+- Checks for existing CODEOWNERS in: `CODEOWNERS`, `.github/CODEOWNERS`, `docs/CODEOWNERS`
+- By default, appends new content to existing CODEOWNERS file
+- With `--overwrite`, replaces the entire CODEOWNERS file
+- Creates CODEOWNERS in the root if it doesn't exist
+- With `--create-pr`, creates a branch and pull request for review
+
+## Examples
+
+Add CODEOWNERS (append mode):
+
+```bash
+node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS
+```
+
+Add CODEOWNERS (overwrite mode):
+
+```bash
+node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --overwrite
+```
+
+Create PRs instead of committing directly:
+
+```bash
+node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --create-pr
+```
+
+Create PRs with custom branch name and title:
+
+```bash
+node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --create-pr --branch my-branch --pr-title "Add CODEOWNERS for compliance"
+```
+
+Dry run to see what would happen:
+
+```bash
+node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --dry-run
+```
+
+With GitHub Enterprise Server:
+
+```bash
+GITHUB_API_URL=https://github.example.com/api/v3 node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS
+```
diff --git a/scripts/add-codeowners-to-repositories/add-codeowners-to-repositories.js b/scripts/add-codeowners-to-repositories/add-codeowners-to-repositories.js
new file mode 100644
index 0000000..6c57823
--- /dev/null
+++ b/scripts/add-codeowners-to-repositories/add-codeowners-to-repositories.js
@@ -0,0 +1,615 @@
+#!/usr/bin/env node
+
+//
+// Adds a CODEOWNERS file to the default branch in a list of repositories
+//
+// Usage:
+//   node add-codeowners-to-repositories.js --repos-file <file> --codeowners <file> [options]
+//
+// Options:
+//   --repos-file <file>   File containing list of repositories (org/repo format, one per line)
+//   --codeowners <file>   Path to the CODEOWNERS file to add
+//   --overwrite           Overwrite existing CODEOWNERS file (default: append)
+//   --create-pr           Create a pull request instead of committing directly
+//   --branch <name>       Branch name for PR (default: add-codeowners)
+//   --pr-title <title>    PR title (default: Add CODEOWNERS file)
+//   --dry-run             Show what would be done without making changes
+//   --concurrency <n>     Number of concurrent API calls (default: 10)
+//   --help                Show help
+//
+// Environment Variables:
+//   GITHUB_TOKEN          GitHub PAT with repo scope (required)
+//   GITHUB_API_URL        API endpoint (defaults to https://api.github.com)
+//
+// Example:
+//   node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS
+//   node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --overwrite
+//   node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --create-pr
+//
+
+import { Octokit } from "octokit";
+import fs from 'fs';
+import { fileURLToPath } from 'url';
+
+// =============================================================================
+// Configuration
+// =============================================================================
+const DEFAULT_CONCURRENCY = 10;
+const DEFAULT_BRANCH_NAME = 'add-codeowners';
+const DEFAULT_PR_TITLE = 'Add CODEOWNERS file';
+
+// Possible CODEOWNERS file locations (in order of preference)
+const CODEOWNERS_PATHS = ['CODEOWNERS', '.github/CODEOWNERS', 'docs/CODEOWNERS'];
+
+// API call counter
+let apiCallCount = 0;
+
+// Parse command line arguments
+function parseArgs() {
+  const args = process.argv.slice(2);
+  const config = {
+    reposFile: null,
+    codeownersFile: null,
+    overwrite: false,
+    createPr: false,
+    branch: DEFAULT_BRANCH_NAME,
+    prTitle: DEFAULT_PR_TITLE,
+    dryRun: false,
+    concurrency: DEFAULT_CONCURRENCY,
+    help: false
+  };
+
+  // Helper to get required argument value
+  const getRequiredValue = (option, index) => {
+    const value = args[index];
+    if (value === undefined || value.startsWith('-')) {
+      console.error(`ERROR: ${option} requires a value`);
+      process.exit(1);
+    }
+    return value;
+  };
+
+  for (let i = 0; i < args.length; i++) {
+    const arg = args[i];
+    switch (arg) {
+      case '--help':
+      case '-h':
+        config.help = true;
+        break;
+      case '--repos-file':
+        config.reposFile = getRequiredValue('--repos-file', ++i);
+        break;
+      case '--codeowners':
+        config.codeownersFile = getRequiredValue('--codeowners', ++i);
+        break;
+      case '--overwrite':
+        config.overwrite = true;
+        break;
+      case '--create-pr':
+        config.createPr = true;
+        break;
+      case '--branch':
+        config.branch = getRequiredValue('--branch', ++i);
+        break;
+      case '--pr-title':
+        config.prTitle = getRequiredValue('--pr-title', ++i);
+        break;
+      case '--dry-run':
+        config.dryRun = true;
+        break;
+      case '--concurrency': {
+        const value = getRequiredValue('--concurrency', ++i);
+        const parsed = parseInt(value, 10);
+        if (isNaN(parsed) || parsed < 1) {
+          console.error(`ERROR: --concurrency must be a positive number`);
+          process.exit(1);
+        }
+        config.concurrency = parsed;
+        break;
+      }
+      default:
+        if (arg.startsWith('-')) {
+          console.error(`ERROR: Unknown option: ${arg}`);
+          process.exit(1);
+        }
+    }
+  }
+
+  return config;
+}
+
+function showHelp() {
+  console.log(`
+Adds a CODEOWNERS file to the default branch in a list of repositories.
+
+Usage:
+  node add-codeowners-to-repositories.js --repos-file <file> --codeowners <file> [options]
+
+Options:
+  --repos-file <file>   File containing list of repositories (org/repo format, one per line)
+  --codeowners <file>   Path to the CODEOWNERS file to add
+  --overwrite           Overwrite existing CODEOWNERS file (default: append)
+  --create-pr           Create a pull request instead of committing directly
+  --branch <name>       Branch name for PR (default: ${DEFAULT_BRANCH_NAME})
+  --pr-title <title>    PR title (default: ${DEFAULT_PR_TITLE})
+  --dry-run             Show what would be done without making changes
+  --concurrency <n>     Number of concurrent API calls (default: ${DEFAULT_CONCURRENCY})
+  --help                Show this help message
+
+Environment Variables:
+  GITHUB_TOKEN          GitHub PAT with repo scope (required)
+  GITHUB_API_URL        API endpoint (defaults to https://api.github.com)
+
+Input File Format:
+  The repos file should contain one repository per line in org/repo format:
+    my-org/repo-1
+    my-org/repo-2
+    other-org/repo-3
+
+  Lines starting with # are treated as comments and ignored.
+  Empty lines are also ignored.
+
+Behavior:
+  - Checks for existing CODEOWNERS in: CODEOWNERS, .github/CODEOWNERS, docs/CODEOWNERS
+  - By default, appends new content to existing CODEOWNERS file
+  - With --overwrite, replaces the entire CODEOWNERS file
+  - Creates CODEOWNERS in the root if it doesn't exist
+  - With --create-pr, creates a branch and pull request for review
+
+Examples:
+  node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS
+  node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --overwrite
+  node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --create-pr
+  node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --create-pr --branch my-branch --pr-title "My PR Title"
+  node add-codeowners-to-repositories.js --repos-file repos.txt --codeowners ./CODEOWNERS --dry-run
+`);
+}
+
+// Shared configuration
+const baseUrl = process.env.GITHUB_API_URL || 'https://api.github.com';
+
+// Create Octokit instance with retry logic
+let octokitInstance = null;
+function createOctokit() {
+  if (octokitInstance) return octokitInstance;
+
+  const token = process.env.GITHUB_TOKEN;
+  if (!token) {
+    console.error("ERROR: GITHUB_TOKEN environment variable is required");
+    process.exit(1);
+  }
+
+  octokitInstance = new Octokit({
+    auth: token,
+    baseUrl,
+    throttle: {
+      onRateLimit: (retryAfter, options, _octokit, retryCount) => {
+        console.error(`Rate limit hit for ${options.method} ${options.url}`);
+        if (retryCount < 3) {
+          console.error(`Retrying after ${retryAfter} seconds...`);
+          return true;
+        }
+        return false;
+      },
+      onSecondaryRateLimit: (retryAfter, options, _octokit, retryCount) => {
+        console.error(`Secondary rate limit hit for ${options.method} ${options.url}`);
+        if (retryCount < 3) {
+          console.error(`Retrying after ${retryAfter} seconds...`);
+          return true;
+        }
+        return false;
+      }
+    }
+  });
+
+  octokitInstance.hook.before('request', () => {
+    apiCallCount++;
+  });
+
+  return octokitInstance;
+}
+
+// Read repositories from file
+function readRepositoriesFile(filePath) {
+  try {
+    const content = fs.readFileSync(filePath, 'utf8');
+    const repos = content
+      .split('\n')
+      .map(line => line.trim())
+      .filter(line => line && !line.startsWith('#'))
+      .map(line => {
+        const parts = line.split('/');
+        if (parts.length !== 2) {
+          console.error(`WARNING: Invalid repository format: ${line} (expected org/repo)`);
+          return null;
+        }
+        return { org: parts[0], repo: parts[1] };
+      })
+      .filter(Boolean);
+
+    if (repos.length === 0) {
+      console.error(`ERROR: No valid repositories found in ${filePath}`);
+      process.exit(1);
+    }
+
+    return repos;
+  } catch (error) {
+    console.error(`ERROR: Failed to read repositories file: ${filePath}`);
+    console.error(error.message);
+    process.exit(1);
+  }
+}
+
+// Read CODEOWNERS file content
+function readCodeownersFile(filePath) {
+  try {
+    return fs.readFileSync(filePath, 'utf8');
+  } catch (error) {
+    console.error(`ERROR: Failed to read CODEOWNERS file: ${filePath}`);
+    console.error(error.message);
+    process.exit(1);
+  }
+}
+
+// Get repository default branch and its SHA
+async function getDefaultBranchInfo(octokit, org, repo) {
+  const { data } = await octokit.rest.repos.get({
+    owner: org,
+    repo
+  });
+  const defaultBranch = data.default_branch;
+
+  // Get the SHA of the default branch
+  const { data: refData } = await octokit.rest.git.getRef({
+    owner: org,
+    repo,
+    ref: `heads/${defaultBranch}`
+  });
+
+  return {
+    name: defaultBranch,
+    sha: refData.object.sha
+  };
+}
+
+// Create a new branch from the default branch
+async function createBranch(octokit, org, repo, branchName, baseSha) {
+  await octokit.rest.git.createRef({
+    owner: org,
+    repo,
+    ref: `refs/heads/${branchName}`,
+    sha: baseSha
+  });
+}
+
+// Create a pull request
+async function createPullRequest(octokit, org, repo, head, base, title, body) {
+  const { data } = await octokit.rest.pulls.create({
+    owner: org,
+    repo,
+    title,
+    body,
+    head,
+    base
+  });
+  return {
+    number: data.number,
+    url: data.html_url
+  };
+}
+
+// Check if CODEOWNERS file exists and return its info
+async function findExistingCodeowners(octokit, org, repo) {
+  for (const path of CODEOWNERS_PATHS) {
+    try {
+      const { data } = await octokit.rest.repos.getContent({
+        owner: org,
+        repo,
+        path
+      });
+      // File exists
+      const content = Buffer.from(data.content, 'base64').toString('utf8');
+      return {
+        exists: true,
+        path,
+        sha: data.sha,
+        content
+      };
+    } catch (error) {
+      if (error.status === 404) {
+        continue; // Try next path
+      }
+      throw error;
+    }
+  }
+
+  // File doesn't exist in any location
+  return {
+    exists: false,
+    path: 'CODEOWNERS',
+    sha: null,
+    content: null
+  };
+}
+
+// Create or update CODEOWNERS file
+async function updateCodeowners(octokit, org, repo, path, content, sha, message, branch = null) {
+  const params = {
+    owner: org,
+    repo,
+    path,
+    message,
+    content: Buffer.from(content).toString('base64')
+  };
+
+  if (sha) {
+    params.sha = sha;
+  }
+
+  if (branch) {
+    params.branch = branch;
+  }
+
+  const { data } = await octokit.rest.repos.createOrUpdateFileContents(params);
+  return {
+    path: data.content.path,
+    sha: data.content.sha,
+    commitDate: data.commit.committer.date
+  };
+}
+
+// Process a single repository
+async function processRepository(octokit, org, repo, newCodeownersContent, config) {
+  const result = {
+    repository: `${org}/${repo}`,
+    status: 'unknown',
+    message: '',
+    path: null,
+    sha: null,
+    prUrl: null
+  };
+
+  try {
+    // Find existing CODEOWNERS file
+    const existing = await findExistingCodeowners(octokit, org, repo);
+
+    let finalContent;
+    let commitMessage;
+
+    if (existing.exists) {
+      if (config.overwrite) {
+        // Overwrite mode: replace entire content
+        finalContent = newCodeownersContent;
+        commitMessage = 'Updating CODEOWNERS file';
+        result.message = 'Replaced existing CODEOWNERS';
+      } else {
+        // Append mode: add new content to existing
+        finalContent = existing.content + '\n' + newCodeownersContent;
+        commitMessage = 'Updating CODEOWNERS file';
+        result.message = 'Appended to existing CODEOWNERS';
+      }
+    } else {
+      // Create new file
+      finalContent = newCodeownersContent;
+      commitMessage = 'Adding CODEOWNERS file';
+      result.message = 'Created new CODEOWNERS file';
+    }
+
+    if (config.dryRun) {
+      result.status = 'dry-run';
+      result.path = existing.path;
+      result.message += config.createPr ? ' (dry-run, would create PR)' : ' (dry-run)';
+      return result;
+    }
+
+    if (config.createPr) {
+      // Get default branch info
+      const defaultBranchInfo = await getDefaultBranchInfo(octokit, org, repo);
+
+      // Create a new branch
+      const branchName = config.branch;
+      try {
+        await createBranch(octokit, org, repo, branchName, defaultBranchInfo.sha);
+      } catch (error) {
+        if (error.status === 422 && error.message.includes('Reference already exists')) {
+          // Branch already exists - could be from a previous run
+          result.status = 'error';
+          result.message = `Branch '${branchName}' already exists. Delete it or use a different branch name.`;
+          return result;
+        }
+        throw error;
+      }
+
+      // Commit to the new branch
+      // Need to get the file info from the new branch (which is same as default at this point)
+      const commitResult = await updateCodeowners(
+        octokit,
+        org,
+        repo,
+        existing.path,
+        finalContent,
+        existing.sha,
+        commitMessage,
+        branchName
+      );
+
+      // Create the pull request
+      const prBody = existing.exists
+        ? `This PR ${config.overwrite ? 'replaces' : 'updates'} the CODEOWNERS file.`
+        : 'This PR adds a CODEOWNERS file to the repository.';
+
+      const pr = await createPullRequest(
+        octokit,
+        org,
+        repo,
+        branchName,
+        defaultBranchInfo.name,
+        config.prTitle,
+        prBody
+      );
+
+      result.status = 'success';
+      result.path = commitResult.path;
+      result.sha = commitResult.sha;
+      result.prUrl = pr.url;
+      result.message += ` (PR #${pr.number})`;
+    } else {
+      // Commit directly to default branch
+      const commitResult = await updateCodeowners(
+        octokit,
+        org,
+        repo,
+        existing.path,
+        finalContent,
+        existing.sha,
+        commitMessage
+      );
+
+      result.status = 'success';
+      result.path = commitResult.path;
+      result.sha = commitResult.sha;
+    }
+
+  } catch (error) {
+    result.status = 'error';
+    result.message = error.message;
+  }
+
+  return result;
+}
+
+// Process repositories with concurrency control
+async function processRepositories(octokit, repositories, codeownersContent, config) {
+  const results = [];
+  const total = repositories.length;
+
+  // Process in batches for concurrency
+  for (let i = 0; i < repositories.length; i += config.concurrency) {
+    const batch = repositories.slice(i, i + config.concurrency);
+    const batchResults = await Promise.all(
+      batch.map((repoInfo, idx) => {
+        const num = i + idx + 1;
+        const pct = Math.round((num / total) * 100);
+        process.stderr.write(`[${num}/${total}] (${pct}%) Processing: ${repoInfo.org}/${repoInfo.repo}\n`);
+        return processRepository(octokit, repoInfo.org, repoInfo.repo, codeownersContent, config);
+      })
+    );
+    results.push(...batchResults);
+  }
+
+  return results;
+}
+
+// Print results summary
+function printSummary(results) {
+  const summary = {
+    success: 0,
+    error: 0,
+    dryRun: 0
+  };
+
+  console.error('\n--- Results ---');
+  for (const result of results) {
+    const statusIcon = result.status === 'success' ? '✓' :
+                       result.status === 'dry-run' ? '○' : '✗';
+    let line = `${statusIcon} ${result.repository}: ${result.message}`;
+    if (result.prUrl) {
+      line += ` - ${result.prUrl}`;
+    }
+    console.error(line);
+
+    if (result.status === 'success') summary.success++;
+    else if (result.status === 'dry-run') summary.dryRun++;
+    else summary.error++;
+  }
+
+  console.error('\n--- Summary ---');
+  if (summary.dryRun > 0) {
+    console.error(`Would update: ${summary.dryRun} repositories`);
+  } else {
+    console.error(`Success: ${summary.success}`);
+    console.error(`Errors: ${summary.error}`);
+  }
+}
+
+// Main function
+async function main() {
+  const config = parseArgs();
+
+  if (config.help) {
+    showHelp();
+    process.exit(0);
+  }
+
+  // Validate required arguments
+  if (!config.reposFile) {
+    console.error("ERROR: --repos-file is required");
+    console.error("Usage: node add-codeowners-to-repositories.js --repos-file <file> --codeowners <file>");
+    console.error("Use --help for more information");
+    process.exit(1);
+  }
+
+  if (!config.codeownersFile) {
+    console.error("ERROR: --codeowners is required");
+    console.error("Usage: node add-codeowners-to-repositories.js --repos-file <file> --codeowners <file>");
+    console.error("Use --help for more information");
+    process.exit(1);
+  }
+
+  // Read input files
+  const repositories = readRepositoriesFile(config.reposFile);
+  const codeownersContent = readCodeownersFile(config.codeownersFile);
+
+  console.error(`Processing ${repositories.length} repositories...`);
+  console.error(`Mode: ${config.overwrite ? 'overwrite' : 'append'}${config.createPr ? ' (create PR)' : ''}`);
+  if (config.dryRun) {
+    console.error('DRY RUN: No changes will be made');
+  }
+  console.error('');
+
+  // Create Octokit instance
+  const octokit = createOctokit();
+
+  // Process repositories
+  const results = await processRepositories(octokit, repositories, codeownersContent, config);
+
+  // Print summary
+  printSummary(results);
+
+  // Display API call count
+  console.error(`\nTotal API calls: ${apiCallCount}`);
+
+  // Exit with error code if any failures
+  const hasErrors = results.some(r => r.status === 'error');
+  if (hasErrors) {
+    process.exit(1);
+  }
+}
+
+// Only run main() if this is the entry point
+const isMainModule = process.argv[1] && fileURLToPath(import.meta.url) === process.argv[1];
+if (isMainModule) {
+  main().catch(err => {
+    console.error(`ERROR: ${err.message}`);
+    process.exit(1);
+  });
+}
+
+// Export functions for testing
+export {
+  parseArgs,
+  readRepositoriesFile,
+  readCodeownersFile,
+  getDefaultBranchInfo,
+  createBranch,
+  createPullRequest,
+  findExistingCodeowners,
+  updateCodeowners,
+  processRepository,
+  processRepositories,
+  createOctokit,
+  CODEOWNERS_PATHS,
+  DEFAULT_CONCURRENCY,
+  DEFAULT_BRANCH_NAME,
+  DEFAULT_PR_TITLE
+};
diff --git a/scripts/add-codeowners-to-repositories/package.json b/scripts/add-codeowners-to-repositories/package.json
new file mode 100644
index 0000000..4427710
--- /dev/null
+++ b/scripts/add-codeowners-to-repositories/package.json
@@ -0,0 +1,25 @@
+{
+  "name": "add-codeowners-to-repositories",
+  "version": "1.0.0",
+  "description": "Add CODEOWNERS file to multiple GitHub repositories",
+  "main": "add-codeowners-to-repositories.js",
+  "type": "module",
+  "scripts": {
+    "start": "node add-codeowners-to-repositories.js",
+    "help": "node add-codeowners-to-repositories.js --help"
+  },
+  "keywords": [
+    "github",
+    "codeowners",
+    "github-api",
+    "octokit"
+  ],
+  "author": "Josh Johanning",
+  "license": "MIT",
+  "engines": {
+    "node": ">=18.0.0"
+  },
+  "dependencies": {
+    "octokit": "^5.0.0"
+  }
+}