She began working onscreen at age 9. Her father was an assistant director for Paramount Pictures. In 1931, she became one of the first Goldwyn Girls, and in 1932 she was seen in Mack Sennett-produced comedies made by Paramount, one starring Bing Crosby. Wing made an impression with producers and moviegoers, but she seldom broke through to leading roles.
Many of her roles were small and barely clothed, before the introduction of the 1934 Production Code, but she became widely recognized as a sex symbol. Since her contracted studio was mired in bankruptcy during much of her career, much of her work was done on loan, primarily at Warner Bros. and later, after her release, on extremely low budget efforts on a per-film basis. Wing enjoyed a far more successful sideline doing product endorsements and was featured in innumerable fan magazines from 1933-38. She was also well known offscreen for her romances, and was linked to Jackie Coogan (to whom she was engaged during much of 1935), Maurice Chevalier, and Franklin D. Roosevelt, Jr.
Toby Wing played a few leading roles in B features and short subjects. In 1936 and 1937, she worked opposite singer-songwriter Pinky Tomlin in two of his low budget musical features, With Love and Kisses and Sing While You're Able. The two stars were engaged briefly during late 1937. Although the romance ended before their planned wedding, they remained close until Tomlin's death.
Her last leading role was in The Marines Come Thru (filmed in Florida in 1938, but not seeing general release until 1942 as Fight On, Marines!). She retired from movies after marrying the pilot Dick Merrill, more than 20 years her senior, on October 19, 1938 in Fredericksburg, Virginia. Wing completed her acting career on Broadway in the unsuccessful Cole Porter musical You Never Know, which starred Lupe Vélez, Clifton Webb, Libby Holman, and J. Harold Murray.