Sally Cary Fairfax (ca. 1730 - 1811, Bath, England) was the wife of George William Fairfax (1729–1787), a prominent member of the landed gentry of late colonial Virginia. As such, she was mistress of the Virginia plantation and estate of Belvoir. She is well-remembered for being the woman George Washington was apparently in love with just before his marriage to Martha Dandridge Custis.
Sally Cary, as she was born, came from one of Virginia's oldest and wealthiest families. Her forefather, Miles Cary of Bristol, England, first came to America in the mid-17th century and established himself as a Virginian nobleman. Colonel Wilson Cary, Sally’s father and a member of the House of Burgesses, inherited one of Virginia’s largest fortunes and the family estate, Ceelys on the James. Little is known about his wife and Sally’s mother, Sarah, on account of an 1826 fire that destroyed many of the family’s records. Out of Colonel Cary’s four daughters, the eldest Sally was the most sought-after and a grande belle in Virginian society. Although she had many suitors, George William Fairfax eventually won Sally’s favor, and in records found by Wilson Miles Cary, a writer and family historian, their marriage was announced in The Virginia Gazette in December 1748. After their marriage, Sally and George William moved into the Belvoir estate that had been established in the early 1740s, by his father Col. William Fairfax.