Wellman was born Dorothy Coonan in Minneapolis, Minnesota. She moved to Los Angeles, California with her family as a child. Her career as a dancer began at the age of 14 with Warner Brothers Studios. Her early film credits as an on-screen dancer and actress included small, uncredited parts in such early talkies as The Broadway Melody (1929), Whoopee! (1930), Kiki (1931) and Palmy Days (1931). Her best-known films were 42nd Street (1933) and Gold Diggers of 1933. Many of the films in which she appeared were choreographed by Busby Berkeley. Film director William Wellman cast Coonan as “Sally” in his 1933 film, Wild Boys of the Road. This was the only role she played in which she was credited or had a character with a name. She makes an uncredited appearance in Wellman’s The Story of G.I. Joe, as an army nurse nicknamed Red who marries a soldier on the battlefield, only to be widowed shortly afterwards. A relationship soon followed and Coonan and Wellman were married in 1934. The couple remained married until she was widowed on December 19, 1975. Dorothy Wellman died in Brentwood, California at the age of 95 in 2009. She was survived by her seven children, twenty-two grandchildren and twelve great-grandchildren.