Born in New Orleans, Louisiana, Dedeaux moved to Los Angeles and graduated from Hollywood High School in 1931. He played baseball at the University of Southern California for three seasons. Dedeaux then played professional baseball briefly in 1935, appearing in two games as a shortstop for the Brooklyn Dodgers. The following year his baseball career ended due to an injury. Dedeaux invested $500 to start a trucking firm, Dart (Dedeaux Automotive Repair and Transit) Enterprises, which he built in