Mary Nesbitt (born 1742/3 – died 1825) was an English upper class socialite and courtesan who mixed in the elevated circles of government and royalty in late 18th century Great Britain.

Mary's enemies, the news sheet Tête-à-tête and the anonymous Junius, attributed his insanity to her disrespectful treatment of him.

[1] On Hervey's death in 1779 Mary received the manor of Evedon, other land in Lincolnshire, and £5000 from the sale of about 186 acres (0.75 km2) in Suffolk.

[1] Her salon at Norwood was frequented by men such as George Rose, secretary to the Treasury, and many young aspirants to political office.

This may indicate that she had been recruited by prime minister William Pitt as a government agent in his covert attempts to restore the French monarchy.

On 25 September 1797, the Morning Chronicle acknowledged that "this celebrated woman", despite "the miscellany of her life", had "acquired an elevation ... which she has preserved with dignity", using "her influence with the great in favour of the unfortunate".