Rex Elvie Allen, born December 31, 1920, to Horace E. Allen and Luella Faye Clark, was an American film actor, singer and songwriter.

Allen was born on a ranch in Mud Springs Canyon, Arizona, 40 miles from Willcox, Arizona.1 His fiddle-playing father gave him his first guitar when he was 11 years old, with the intention that Rex would play backup for him at local dances. For a while Rex played guitar and sang at local these functions but when he graduated from high school, he left home to tour the southwest as a rodeo rider. However his career on the rodeo circuit was short-lived, due to an injury from a bull, so he went back to singing.

Allen got his start in show business as a vaudeville singer, and was hired by WTTM in Trenton, NJ, in 1943.