John Derran Lackey (born October 23, 1978) is an American former professional baseball starting pitcher who played in Major League Baseball from 2002 through 2017 for the Los Angeles Angels of Anaheim, Boston Red Sox, St. Louis Cardinals and Chicago Cubs. A three-time World Series champion with three different teams, Lackey is regarded as a key figure in his clubs' postseason success, winning the title-clinching games of two out of the three Series. Selected to the MLB All-Star Game in 2007, he won that year's American League (AL) earned run average (ERA) title. After missing the 2012 season due to ulnar collateral ligament reconstruction surgery in his pitching elbow, and helping the Red Sox win the 2013 World Series, Lackey was named the winner of the Tony Conigliaro Award.

A right-handed pitcher and batter, the Anaheim Angels selected Lackey from Grayson County College in Texas in the 1999 amateur draft. He made his MLB debut with the Angels in 2002 and helped the franchise win its first World Series title that year. After winning more than 100 games with the Angels, Lackey signed with Boston in free agency prior to the 2010 season. Declining performance and elbow injuries in 2011 led him to allow the most earned runs in the American League before missing the next season due to elbow surgery. Lackey rebounded in 2013 to win his second championship. Boston traded him to St. Louis in July 2014, and prior to the 2016 season, he signed with Chicago as a free agent. Lackey earned his third World Series championship in 2016 with the Cubs.

Known for his intense competitiveness and overall durability, Lackey reached at least 200 innings pitched six times in his career, and in five seasons was in the top ten in games started. With the exception of his rookie season in 2002, he reached at least 10 wins every season of his career. In ten of his 15 seasons, he registered an ERA below 4.00 − once below 3.00 − and four times was in the top ten in ERA. He also twice reached the top ten in both wins and strikeouts. He appeared in ten postseasons overall, recording a career 8-6 record and 3.44 ERA over 144 innings. In 2007 and 2015, he received votes for the Cy Young Award.