William Hopper

as Colonel Robert Calder

as Dr. Nedrick 'Ned' Jackson

as Col. Kenneth Penmark

as William Barrett Travis

as Judy's Father

as 'Mac' MacBain

as Smokey

as Dr. George Fenton

as Arthur Bridges

as Charles Wentworth

as University of Texas Classmate (uncredited)

as John

as Billiards player

as Pilot

as Private Turner

as Reporter

as John

as Sergeant (uncredited)

as Matt, a Reporter