William Sylvester (1922-1995) was an American actor, primarily active in British film and television. He is universally recognized for his iconic role as Dr. Heywood Floyd in Stanley Kubrick's masterpiece, *2001: A Space Odyssey* (1968), where his calm and authoritative performance is central to the narrative.

Beyond this, his film career includes the science fiction film *Gorgo* (1961), in which he played the protagonist Joe Ryan, and the war drama *The Man Who Never Was* (1956).

Sylvester often specialized in portraying authoritative and intellectual characters, such as scientists, military officers, or professionals. His acting style was characterized by a calm, dependable, and often measured presence, allowing him to portray commanding or supporting figures with credibility. He was a prolific actor, though primarily in supporting roles, leaving a distinctive mark on genre and auteur cinema.