List of baseball players who underwent Tommy John surgery

Tommy John surgery (TJS), known in medical practice as ulnar collateral ligament (UCL) reconstruction, is a surgical graft procedure in which the ulnar collateral ligament in the medial elbow is replaced with either a tendon from elsewhere from the patient's own body, or the use of a tendon from the donated tissue from a cadaver. The procedure is common among collegiate and professional athletes in several sports, most notably baseball.

The procedure was first performed in 1974 by orthopedic surgeon Dr. Frank Jobe, then a Los Angeles Dodgers team physician. The surgery is named after Tommy John, the first recipient of the surgery. John won 288 games in his career – 124 before the surgery and 164 after. Many players have subsequently undergone the surgery, some more than once. Two players (Paul Molitor and John Smoltz) have undergone the surgery and been inducted into the National Baseball Hall of Fame. Bryce Harper tore his UCL in April of 2022. Harper would play the rest of the season as the designated hitter and win the NLCS MVP for the Phillies. He would undergo the surgery shortly after the World Series loss and come back to hit in May 2023, which is one of the fastest recovery times for the surgery.

List
† Denotes a player that underwent the surgery on his non-throwing arm.