Liberty Mutual Insurance Company, often referred to as Liberty Mutual Insurance, is an American diversified global insurer and the sixth-largest property and casualty insurer in the world. It ranks 91st on the Fortune 100 list of largest corporations in the United States based on 2025 revenue. Based in Boston, Massachusetts, it employs over 45,000 people in more than 900 locations throughout the world. As of December 31, 2021, Liberty Mutual Insurance had $156.043 billion in consolidated assets, $128.195 billion in consolidated liabilities and $48.2 billion in annual consolidated revenue.