William A. Haseltine is an American biologist, entrepreneur and philanthropist. He is known for his groundbreaking work on HIV/AIDS and the human genome. Haseltine was a professor at Harvard Medical School where he founded two research departments on cancer and HIV/AIDS. Haseltine is a founder of several biotechnology companies including Cambridge Biosciences, The Virus Research Institute, ProScript, LeukoSite, Dendreon, Diversa, X-VAX, and Demetrix. He was a founding chairman and CEO of Human Genome Sciences, a company that pioneered the application of genomics to drug discovery. He is the president of the Haseltine Foundation for Science and the Arts and is the founder, chairman, and president of ACCESS Health International, a not-for-profit organization dedicated to improving access to high quality health worldwide. He has been and continues to be listed by Time Magazine as one of the world's 25 most influential business people in 2001 and one of the 100 most influential leaders in biotechnology by Scientific American in 2015.