Louis Jean Heydt (April 17, 1903 – January 29, 1960) was an American character actor in film, television and theatre, most frequently seen in hapless, ineffectual, or fall guy roles.

[7] After he left the Broadway production of The Trial of Mary Dugan, Heydt acted in stock theatre with the Alice Brady Company in Buffalo, Rochester, and Toronto.

He made an impression as an older, warm-hearted soldier in the 1945 John Ford PT-boat epic They Were Expendable, and co-starred in the 1951 film noir Roadblock in support of Charles McGraw.

[9][10] Heydt guest starred on the Adventures of Superman, Treasury Men in Action, Cavalcade of America, TV Reader's Digest, Crossroads, Lux Video Theatre, Fury, The Man from Blackhawk, Wagon Train, and Maverick.

[12] Heydt died of a heart attack on January 29, 1960, in Boston, where he collapsed immediately after leaving the stage following the first scene of a pre-Broadway performance of the play, There Was a Little Girl, in which he appeared opposite Jane Fonda.