Thomas Albert Ecke Van Dekker (December 20, 1905 – May 5, 1968) was an American actor and politician known for his roles in Dr. Cyclops, The Killers (1946), Kiss Me Deadly, and The Wild Bunch.

He replaced Lee J. Cobb as Willy Loman in the original production of Arthur Miller's Death of a Salesman, and during a five-year stint back on Broadway in the early 1960s, he played the Duke of Norfolk in Robert Bolt's A Man for All Seasons.

Dekker appeared in some 70 films from the 1930s to the 1960s, but his four famous screen roles were as a mad scientist in the 1940 horror film Dr. Cyclops, as a criminal mastermind in 1946's The Killers, as a dangerous dealer in atomic fuel in the 1955 Kiss Me Deadly, and as an unscrupulous railroad detective in Sam Peckinpah's Western The Wild Bunch, released in 1969.

Dekker was an often memorable guest star – usually a villain – in numerous TV series from the 1950s through 1968, such as Rawhide, The Man From UNCLE, Mission: Impossible, Climax!, Bonanza, and I Spy.

Stratton describes Dekker as "completely nuts," and possibly the most troubled person on a set filled with eccentrics.

[8] On May 5, 1968, Dekker was found dead in his Hollywood home by his fiancée, fashion model and future Love Boat creator Jeraldine Saunders.

Police, calling it "quite an unusual case",[10] originally said it was suicide but the deputy coroner found no evidence of foul play nor any indication that he planned to take his life and ruled his death accidental, the result of autoerotic asphyxiation.