William Lewis Douglas (August 22, 1845 – September 17, 1924) was an American businessman and politician from Massachusetts. He served as the 42nd Governor of Massachusetts from 1905 until 1906. He also founded and oversaw the growth of the W. L. Douglas Shoe Company, a highly successful Brockton, Massachusetts business that became one of the world's largest shoe manufacturers. He also opened the first nationwide chain of shoe stores devoted to selling the company's products.

Douglas received a minimal education and was apprenticed into the shoe trade. In 1876, he established his business, which grew rapidly over the next twenty years. He entered politics as a supporter of labor and an opponent of socialism, and funded his 1904 campaign for governor. In addition to labor causes, he supported reciprocity and tariff reductions in trade with Canada. He refused to run for reelection, and returned to his business.