Voted a 1928 WAMPAS Baby Star by motion picture advertisers, piquant Molly O'Day (born Noonan) had followed her older sister, Sally O'Neil, into films in 1925. After a stint with Hal Roach, the slightly chubby flapper skyrocketed to stardom opposite heartthrob Richard Barthelmess in The Patent Leather Kid (1927). The role was a victory of sorts since her studio, First National, at first had refused to see her as leading lady material. But the victory came with a price tag: To get herself ready for the demanding role of a dancehall girl-turned-war nurse, O'Day began a battle with obesity that would eventually ruin both her career and her health.
The problems only intensified on the set of the pastoral romance Little Shepherd of Kingdom Come (1928), again opposite Barthelmess, and the studio brought in a dietician. But while munching away on spinach and pineapple in public, the private Molly O'Day reportedly went to town on "ice cream, cream puffs, and chocolate candy." Returning from location, even her most ardent supporter, producer Al Rockett, failed to recognize her and felt forced to lay down the law. "As far as we're concerned, you're through," Rockett is supposed to have yelled, "that is until you get down to the right physical size for our pictures!" Her roles, the producer added, would instead go to Alice White. O'Day checked herself into a health spa in Arkansas where she supposedly underwent dramatic surgery that literally cut off the unwanted poundage. The results were decades of ill health and unseemly scars running up and down her body.
O'Day returned to the limelight via a vaudeville tour with sister Sally O'Neil and they both appeared in the famous "sisters" act in Warner Bros.' The Show of Shows (1929). The following year, Columbia hired them for Sisters (1930), a flop, and she was forced to declare bankruptcy. She was the most memorable performer in something called Gigolettes of Paris (1933), a Poverty Row comedy-drama in which she played that Hollywood B-movie stable, the heroine's wisecracking girlfriend, and she proved surprisingly subtle as Ann Harding's kindhearted friend in The Life of Vergie Winters (1934). Her subsequent opportunities were few and far between, however, and she left films altogether in 1935. Offscreen, O'Day married nightclub comedian Jack Durant, with whom she had four children before they divorced in 1951. A second marriage, to oilman James Kenaston, lasted a mere four years and she spent the remainder of her life as a real estate agent in Avila Beach, CA, happily answering questions about her long-ago screen career while at the same time denouncing some of the more outrageous claims concerning her once very public battle with the bulge.