John Eastman was an American lawyer who was the brother of Linda Eastman and Paul McCartney's brother-in-law. He represented Paul McCartney as his lawyer from the Beatles' breakup in 1970 and onwards, until his death in 2022.
Eastman entered McCartney's life when he married Linda. Eastman and his father, Lee Eastman, began representing McCartney during the Beatles' breakup and continued on to represent McCartney throughout his solo career.