John Korir (born 2 December 1996) is a Kenyan road runner. He was the winner of the 2024 Chicago Marathon, in a time of 2:02:44, making him the sixth fastest marathoner in history. He won the 2025 Boston Marathon in a time of 2:04:45, which his brother Wesley Korir also won in 2012, making them the first brothers to win Boston.