[1] By December 1924, he headed the Frank Wilcox Company, which produced plays in venues that included the Lyceum in Baltimore.

[4] Wilcox became a contract player for Warner Bros., beginning with the 1939 short film The Monroe Doctrine,[citation needed] in which he was chosen to portray the American statesman Henry Clay during the early 1820s.

He played Abraham Lincoln as a militia captain in another 1939 film short Old Hickory, based on key events in the public career of President Andrew Jackson.

[1] Another film role was as the circus doctor in the 1952 production The Greatest Show on Earth, starring Charlton Heston.

His best known television role, the one which brought him great recognition from millions of viewers, was that of the oil executive John Brewster in the first five seasons of The Beverly Hillbillies.

Wilcox made several guest appearances as a judge on Perry Mason during the nine-year run of that program.

His hometown of De Soto, Missouri hosts the Frank Wilcox Film Festival every March during the weekend closest to his birthday.