Hayden was born Pate Lucid. After working behind the scenes in films as a grip, sound recorder, film cutter, and assistant cameraman, he began acting in films in the mid '30s. Between 1937-41 he played Lucky Jenkins, William Boyd's saddle pal, in 27 Hopalong Cassidy Westerns. He starred in his own Western series in the '40s, and in 1943-44 he was voted one of the Top Ten Cowboy stars; he also costarred with James Ellison in numerous Westerns which he co-produced, and occasionally had leads in non-Westerns as well as one adventure serial. Beginning in the early '50s (when he retired from films) he produced and directed TV Westerns, including the series 26 Men and Judge Roy Bean, starring in the latter. He married and divorced actress Jan Clayton, who was his leading lady in some of the Hopalong Cassidy films. Later he married actress Lillian Porter.