William Henry Andrews (born December 10, 1951) is an American molecular biologist and gerontologist whose career has centered on searching for a cure for human aging. Andrews is the founder and president of the biotechnology company Sierra Sciences. In the 1990s, he led the team at Geron Corporation that was the first to successfully identify the genes for human enzyme telomerase. This enzyme is responsible for preventing telomeres from shortening in human primordial germ cells (reproductive cells).