Jo Sullivan Loesser is a singer and actress whose Off-Broadway career includes the role of Polly Peachum in THE THREEPENNY OPERA (1954) at the Theatre de Lys, which is now the Lucille Lortel Theatre. During this production, she shared the stage with Bea Arthur and Lotte Lenya. The show had an original run for three months in 1954. It was then revived in 1955 and ran until 1961; Loesser performed for nine months in this revival.

Loesser was born in Mounds, Illinois on August 28, 1927; growing up, she studied piano and voice. When she was 17, she moved to St. Louis to continue her studies, and then relocated to New York in 1946. Her Broadway credits include: Sleepy Hollow (1948), As the Girls Go (1948), Let's Make an Opera (1950), Carousel (1954), and Perfectly Frank (1980). She married songwriter Frank Loesser and didn't perform during her marriage from 1959-1969. Loesser was nominated for a Tony Award for Best Featured Actress in 1957 for her performance as Rosabella in The Most Happy Fella.