Carlisle dated George Gershwin in 1933 "until George went to California".
On August 10, 1946, she married playwright and theatrical producer Moss Hart, whom she met at the Bucks County Playhouse in New Hope, Pennsylvania.
They had two children, but Hart died on December 20, 1961, at their home in Palm Springs, California.
She never remarried, although she briefly dated former governor and presidential candidate Thomas E. Dewey after the death of his wife.
 During the 1980s and 1990s, Carlisle was the partner of diplomatic historian Ivo John Lederer, a relationship that lasted 16 years until Lederer's death in 1998.
In her later years, she kept company with financier and art collector Roy Neuberger.

Carlisle was known for her gracious manner and personal elegance, and she became prominent in New York City social circles as she crusaded for financial support of the arts.
She was appointed to various statewide councils, and was chairman of the New York State Council on the Arts from 1976 to 1996.
One of the two state theaters housed at The Egg performing arts venue in Albany is named the Kitty Carlisle Hart Theatre in her honor.
She also served on the boards of various New York City cultural institutions and made an appearance at the annual CIBC World Markets Miracle Day, a children's charity event.
She was elected a Fellow of the American Academy of Arts and Sciences in 1997.

She also widely performed her one-woman show in which she told anecdotes about the many great men in American musical theater history whom she had known, notably George Gershwin (who had proposed marriage), Irving Berlin, Kurt Weill, Oscar Hammerstein, Alan Jay Lerner, and Frederick Loewe, interspersed with a few of the songs that made each of them famous.
Carlisle dated George Gershwin in 1933 "until George went to California". On August 10, 1946, she married playwright and theatrical producer Moss Hart, whom she met at the Bucks County Playhouse in New Hope, Pennsylvania. They had two children, but Hart died on December 20, 1961, at their home in Palm Springs, California. She never remarried, although she briefly dated former governor and presidential candidate Thomas E. Dewey after the death of his wife.  During the 1980s and 1990s, Carlisle was the partner of diplomatic historian Ivo John Lederer, a relationship that lasted 16 years until Lederer's death in 1998. In her later years, she kept company with financier and art collector Roy Neuberger.
Carlisle was known for her gracious manner and personal elegance, and she became prominent in New York City social circles as she crusaded for financial support of the arts. She was appointed to various statewide councils, and was chairman of the New York State Council on the Arts from 1976 to 1996. One of the two state theaters housed at The Egg performing arts venue in Albany is named the Kitty Carlisle Hart Theatre in her honor. She also served on the boards of various New York City cultural institutions and made an appearance at the annual CIBC World Markets Miracle Day, a children's charity event. She was elected a Fellow of the American Academy of Arts and Sciences in 1997.
She also widely performed her one-woman show in which she told anecdotes about the many great men in American musical theater history whom she had known, notably George Gershwin (who had proposed marriage), Irving Berlin, Kurt Weill, Oscar Hammerstein, Alan Jay Lerner, and Frederick Loewe, interspersed with a few of the songs that made each of them famous.
Kitty Carlisle