Sir Frederick Beilby Watson, KCH, FRS (1773–11 July 1852) was a British courtier. Watson was the son of William Watson, who was Ranger of Books (i.e. librarian) at the Treasury, and Elizabeth, née Beilby. In 1805 he became Paymaster of the 1st The Royal Dragoons. On 1 July 1815, he was appointed Assistant Private Secretary to The Prince Regent. Prior to that appointment he had been Private Secretary to the Duke of Cumberland. On 11 July 1852, Watson died at his home on New Place, St John's Wood, aged 80. He is buried at Kensal Green Cemetery.