Ruth Kobart (April 24 1924 – December 14 2002) was an American character actress whose six-decade career encompassed opera, Broadway musical theatre, regional theatre, films, and television.

Born as Ruth Maxine Finkelstein in Des Moines, Iowa, Kobart studied opera at the American Conservatory of Music in Chicago and made her professional debut as the Witch in an off-Broadway production of Engelbert Humperdinck's Hänsel und Gretel. She frequently toured with the NBC opera company and the New York City Opera.

In 1953, Kobart made her Broadway debut in the chorus of Rodgers and Hammerstein's Pipe Dream. She also understudied leading lady Helen Traubel and played her role twenty times times during the show's run. Additional Broadway credits included Maria Golovin, How to Succeed in Business Without Really Trying, A Funny Thing Happened on the Way to the Forum, A Flea in Her Ear, and The Three Sisters. She was nominated for the 1963 Tony Award for Best Featured Actress in a Musical for Forum.

Kobart's association with San Francisco's American Conservatory Theater began with its first season in 1967 and lasted through 1994. Her appearances with them included The House of Bernarda Alba, Sunday in the Park with George, Arsenic and Old Lace, and Home. In the 1970s she took an extended leave from the company to portray Nurse Ratched in the 18-month-long San Francisco production of One Flew Over the Cuckoo's Nest.

Kobart's national tour credits included Forty Carats, The Last of the Red Hot Lovers, and Annie. On screen she appeared in the feature film adaptation of How to Succeed as well as Petulia, Dirty Harry, The Hindenburg, Sister Act, and Sister Act 2: Back in the Habit.

Her television credits included a regular role on Bob and guest appearances on CHiPs, Archie Bunker's Place, St. Elsewhere, Matt Houston, Remington Steele, Midnight Caller, and Murphy Brown.

Kobart died of pancreatic cancer at her home in San Francisco, aged 78, seven months after being diagnosed with the illness.

Classical and musical comedy character actress, a long time member of San Francisco's ACT, known for her Broadway work, particularly her roles in "How to Succeed in Business Without Really Trying" (1961), which she transferred to film six years later, and "A Funny Thing Happened on the Way to the Forum" (1962), which earned her a Tony-nomination. She typically played overbearing wives and shrewish-like roles.

Was an opera singer before entering the world of musical comedy and movies.

Was nominated for Broadway's 1963 Tony Award as Best Supporting or Featured Actress (Musical) for "A Funny Thing Happened on the Way to the Forum."