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.

Two players (Paul Molitor and John Smoltz) have undergone the surgery and been inducted into the National Baseball Hall of Fame.

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

Tommy John was the first baseball player to undergo the surgery.
Paul Molitor was the first player who underwent the surgery to be elected to the Hall of Fame .
José Mesa was one of the first players born outside the United States to undergo the surgery.
John Farrell was perhaps the first player to undergo the surgery twice.
Scott Schoeneweis was one of the first players to undergo the surgery while in college .
Dewon Brazelton was one of the first players to undergo the surgery while in high school.
Jay Payton was one of the first position players to undergo the surgery twice.
John Smoltz was the first pitcher who underwent the surgery to be elected to the Hall of Fame.
Jamie Moyer is the oldest player to undergo the surgery.
Zack Cozart was the first player to undergo the surgery on his non-throwing arm.
Jonny Venters is one of the only players to undergo the surgery more than two times.