Donald was born into a theatrical family. Donald's father Chuck was a professional boxer and circus performer. Donald was put on Stage at 13 months old, doing things like hand stands with his family's act.

    When Donald's father passed away his mother kept the act going, developing their act into a successful Vaudeville routine. Donald's mother taught him such dances as Buck, Tap, Black Bottom and was doing routines and by four years old his comedic dancing would became a big part of the routine.

    When he was sixteen years of age he was part of a swing dance troupe called the Jivin Jack's and Jill's with partner Peggy Ryan who he would partner in many of his earlier Films. Later he got his formal dance training from Johnny Boyle and Louis DaPron. He entered the movies with then famous Bing Crosby

in "Sing You Sinners" in 1938 when a studio executive saw his act. Later Louis DaPron was a major influence in his dance ability.

    From 1944 to 1947, Donald entered the Army, while there he made over 2000 personal appearances for the Special Services. Most people were familiar with O'Conner in the "Francis and the Talking Mule" series. However his real big break came with the movie "Singin' in the Rain" with Gene Kelly.