W illiam R. Berkley is a self-made American billionaire and a major figure in the insurance industry. He is the founder and executive chairman of W. R. Berkley Corporation, a major property and casualty insurance holding company. He founded the company in 1967 with a small investment while he was still a student at Harvard Business School. He has since built it into a Fortune 500 company through a strategy of focusing on niche, specialty insurance markets that were often overlooked by larger competitors.

He has served as the company's longtime chairman and CEO for decades, building a reputation as a shrewd underwriter and a savvy investor. W. R. Berkley Corporation is also known for its decentralized operating model, which gives a high degree of autonomy to its various operating units. He has since passed on the CEO title to his son, W. Robert Berkley Jr., but he remains the executive chairman and the company's largest shareholder. He is also a major philanthropist and serves as the chairman of the board of trustees for New York University.