William Henry Pratt (23 November 1887 – 2 February 1969), known professionally as Boris Karloff () and occasionally billed as Karloff the Uncanny, was an English actor. His portrayal of Frankenstein's monster in the horror film Frankenstein (1931) (his 82nd film) established him as a horror icon, and he reprised the role for the sequels Bride of Frankenstein (1935) and Son of Frankenstein (1939). He also appeared as Imhotep in The Mummy (1932), and voiced the Grinch in, as well as narrating, the animated television special of Dr. Seuss' How the Grinch Stole Christmas! (1966), which won him a Grammy Award.

Aside from his numerous film roles (174 films), Karloff acted in many live stage plays and appeared on dozens of radio and television programs as well. For his contribution to film and television, Karloff was awarded two stars on the Hollywood Walk of Fame on 8 February 1960.