Gladys Swarthout (born December 25, 1900, Deepwater, Missouri – died July 7, 1969, Florence, Italy) was an American mezzo-soprano opera singer and entertainer. 　　While studying at the Bush Conservatory of Music in Chicago, a group of friends arranged an audition for her with the Chicago Civic Opera Company. Much to her surprise, she ended up with a contract, though at the time she didn't know a single operatic role. When she debuted a few months later, she had memorized 23 parts and participated in over half of the season's operas. She sang for the Ravinia Opera Company of Chicago for three seasons. In 1929, she made her debut with the New York Metropolitan Opera Company, where she sang in over 270 performances until her Gala Farewell on April 16, 1966. 　　Swarthout's role as Carmen was well respected. She regularly worked eight hours a day with vocal coaches, and would spend an hour or more singing duets with her husband, Frank Chapman, also an opera singer. She also advocated inflating balloons and blowing bubbles to strengthen her lungs. She also wrote a semi-autobiographical novel entitled Come Soon, Tomorrow: The Story of a Young Singer first published in 1943 that went through at least seven printings.