Andy Messersmith (born August 6, 1945 in Toms River, New Jersey) is a former Major League Baseball right-handed starting pitcher from 1968 until 1979. He was the 12th overall pick of the 1966 amateur draft by the California Angels. Messersmith went on to play for the Los Angeles Dodgers, Atlanta Braves and the New York Yankees.
Messersmith is most famous for his role in the historic 1975 Seitz decision which led to the downfall of Major League Baseball's reserve clause and ushered in the current era of free agency.
Messersmith and Dave McNally were the only two players in 1975 playing on the one year reserve clause in effect at the time. Neither had signed a contract at the time but both were held with their team under the rule. The two challenged the rule and won their free agency.