Born Joseph Shovlin on June 30, 1902, in Wilkes-Barre, Penssylvania, he took piano lessons as a child but the talent never went anywhere. He eventually was hired by the Woolworths department store chain and worked his way up to manager by the time he resigned at the age of 23. During an extensive period of travel, he stopped in New York City and became hooked on acting after catching a Broadway show. He apprenticed and made his stage debut with Eva Le Gallienne's repertory company. To make do, the handsome hopeful worked as an artist's model, including the renowned 'James Montgomery Flagg'.
Whalen came to Hollywood in 1933 and started out on the L.A. stage with roles in "When Knighthood Was in Flower" (as the Dauphin) and "Common Flesh." Noticed by Twentieth Century-Fox talent agents, he made his debut with a second-lead role in Professional Soldier (1935) starring Victor McLaglen. On screen he appeared opposite a bevy of Hollywood lovelies, notably Alice Faye, Gloria Stuart, Claire Trevor and June Lang, in standard "B" filmmaking, playing a series of virile, flashy roles including Hollywood producers and sports editor types. He also had the adult male leads in two of little Shirley Temple's popular vehicles -- Poor Little Rich Girl (1936) and Wee Willie Winkie (1937). In 1938 he starred as newsman Barney Callahan in a string of murder mystery tales (Time Out for Murder (1938), While New York Sleeps (1938) and Inside Story (1939)) alongside love interest Jean Rogers.
By the early 1940s his leading man career started to falter. He went to Broadway for two years in "Ten Little Indians" (1944), then toured with the show on the road. By the 1950s he was appearing less frequently on film and more and more into character roles. TV became a source of income for him. His last movie was an unbilled bit in Elmer Gantry (1960), and in 1964 he made his final appearance on an episode of "My Three Sons" (1960).
Whalen remained a bachelor and lived with his mother until her death in the 1960s. He collected antiques and enjoyed gardening until his death of bronchial pneumonia in 1974 at age 71.