Sara Berner (born Lillian Ann Herdan; January 12, 1912 – December 19, 1969) was an American actress. Known for her expertise in dialect and characterization, she began her career as a performer in vaudeville before becoming a voice actress for radio and animated shorts. She starred in her own radio show on NBC, Sara's Private Caper, and was best known as telephone operator Mabel Flapsaddle on The Jack Benny Program.

Columnist Erskine Johnson described Berner in 1944 as "the most famous voice in Hollywood."

Born Lillian Ann Herdan in 1912 in Albany, New York, she adopted her stage name by combining her mother's first name (Sarah) and her maiden name of Berner. She was the oldest of four children, and her family relocated to Tulsa, Oklahoma when she was a teenager. She became interested in performing after watching silent movies and vaudeville shows at a theater and then imitating scenes in front of the women's restroom attendant.

Berner performed in an adaptation of Abie's Irish Rose after graduation, and she studied drama for two years at the University of Tulsa. She and her family then moved to Philadelphia, Pennsylvania, where she worked in a Wanamaker's department store until she was fired for mimicking a customer. Berner hosted her own fifteen-minute program (written by Arthur Q. Bryan) thereafter on a local radio station, then returned to New York City in hopes of pursuing a show-business career. She worked in a Broadway millinery in the meantime, and studied dialect by observing customers' Brooklyn accents. She sneaked out during a shift to audition for Major Edward Bowes's amateur hour, and was hired the next day. Beginning in 1937, Berner toured the country as part of Bowes's sixteen-member "all-girl unit" of vaudeville acts over the next four years, and created a gimmick of a fired saleslady who performed imitations of celebrities such as Mae West and Katharine Hepburn.

After the Major Bowes tour ended, Berner began working in network radio in Hollywood, with recurring roles on Fibber McGee & Molly and The George Burns and Gracie Allen Show. On The Jack Benny Program, she voiced one-time parts before joining the principal cast as the recurring characters of Jack Benny's girlfriend Gladys Zybisco, and wisecracking telephone operator Mabel Flapsaddle, who gossiped about Benny with her colleague Gertrude Gearshift (Bea Benaderet), while Benny waited impatiently on the other end of the line for them to connect his call. Intended as a one-time appearance, they began recurring roles in the 1945–46 season, and in early 1947, Berner and Benaderet momentarily took over the actual NBC switchboards in Hollywood for publicity photos. Other radio work included waitress Dreamboat Mulvany on Arthur's Place; Mrs. Horowitz on Life with Luigi; Helen Wilson on Amos 'n' Andy; and an Italian housekeeper on The Jimmy Durante Show. She was cast alongside Rudy Vallée on his show The Fleischmann's Yeast Hour; however, she sued Vallée in 1945 for $19,500 in damages over claims he reneged on an "oral agreement" that he would hire her for 39 appearances on his show at $500 weekly.

As a result of her radio successes, Berner was given her own series on NBC, Sara's Private Caper, in which she starred as a police department stenographer who moonlighted as an amateur sleuth to solve crimes. Billed as "a satire on private detective stories" that claimed to feature Berner's actual voice, the show premiered on June 15, 1950, but was canceled after just eleven weeks, with its final broadcast on August 24. It had been hampered by multiple title changes prior to its debut, as well as confusion over whether to market the program as a mystery, comedy, or drama. Berner returned to supporting roles, but was temporarily removed from The Jack Benny Program for an eighteen-month period between 1954 and 1955 due to an undisclosed dispute with Benny, and was substituted by Shirley Mitchell as Mabel Flapsaddle in that duration.

Berner was active in vocal characterization for animated cartoons, working with several studios from the late 1930s through the 1940s. She was initially utilized for her imitations of Hollywood film actresses, such as Katharine Hepburn, Bette Davis, Joan Crawford, and Martha Raye. This led to her being cast in celebrity-ensemble shorts such as Disney's Mother Goose Goes Hollywood (1938) and The Autograph Hound (1939); Walter Lantz Productions' Hollywood Bowl (1938); and Warner Bros.' Hollywood Steps Out (1941).

Her mimicking of Hepburn led to her being hired by Lantz as the debut voice of Andy Panda, which she played only twice, in Life Begins for Andy Panda (1939) and Knock Knock (1940). Berner focused on voicing animals thereafter, with her work for Warner Bros. Cartoons (where she replaced Bernice Hansen) ranging from Mama Buzzard in Bugs Bunny Gets the Boid (1942) and The Bashful Buzzard (1945); to A. Flea in the short An Itch in Time (1943); and as part of an ensemble of voices in Book Revue (1946). For the Metro-Goldwyn-Mayer cartoon studio, Berner portrayed minor characters in the Tom and Jerry shorts The Zoot Cat (1944) and The Mouse Comes to Dinner (1945). In the MGM live-action film Anchors Aweigh (1945), she voiced the otherwise-silent Jerry Mouse for the animated dance sequence with star Gene Kelly.