Adele Astaire Douglass (born Adele Marie Austerlitz, later known as Lady Charles Cavendish; September 10, 1896 – January 25, 1981), was an American dancer, stage actress, and singer. After beginning work as a dancer and vaudeville performer at the age of nine, Astaire built a successful performance career with her younger brother, Fred Astaire.

The brother and sister act initially worked their way through vaudeville circuits, finally achieving a breakthrough with their first Broadway roles in 1917. Astaire became known for her talents as a skilled dancer and comedienne, starring in hit Broadway musicals such as Lady, Be Good! (1924), Funny Face (1927) and The Band Wagon (1931). The siblings took several of their more popular shows to Britain's West End during the 1920s, where they were soon international celebrities, meeting members of the British royal family and prominent figures from contemporary arts and literature circles.

In 1932, after a 27-year partnership with her brother, Astaire retired from the stage to marry Lord Charles Arthur Francis Cavendish, the second son of Victor Cavendish, 9th Duke of Devonshire. The couple moved to the Cavendish estate of Lismore Castle in Ireland. Despite offers of both stage and film roles from producers eager to see her return to acting, Astaire declined to come out of retirement. Following Cavendish's death in 1944, Astaire remarried and moved back to the United States. She divided her time between properties in the United States; Round Hill, Jamaica; and her old home of Lismore Castle, where she spent her summers up until the end of her life.

In 1972, Astaire was inducted into the American Theater Hall of Fame.

In 1975, Astaire was inducted into the International Best Dressed Hall of Fame List.