William Simpson is a partner in the Corporate practice of Paul Hastings. He focuses his practice on private equity, mergers and acquisitions and venture capital. He regularly represents owners and management groups in private equity transactions and he currently represents over 30 private equity backed companies and 10 private equity and other investment groups. He has handled approximately 250 mergers and acquisitions, including the sale of Linksys to Cisco and the sale of Pacific Scientific to Danaher.

Mr. Simpson serves as chair of the firm's Global Private Equity practice. He has also formerly served as the chair of firm’s Orange County Office and chair of the Business and Corporate Law Section of the Orange County Bar Association.