Grant Williams (born John Joseph Williams; August 18, 1931 – July 28, 1985) was an American film, theater and television actor. He is best remembered for his portrayal of the title character Scott Carey in the science fiction film The Incredible Shrinking Man (1957) and for his starring role as Greg MacKenzie in Hawaiian Eye from 1960 to 1963.

He played Major Douglas McKinnon in the original series episode "The Brain of Colonel Barham".