Henry Louis "Lou" or "Buster" Gehrig (Born Heinrich Ludwig Gehrig; June 19, 1903 June 2, 1941) was an American baseball first baseman who played 17 seasons in Major League Baseball (MLB) for the New York Yankees, from 1923 through 1939. Gehrig was renowned for his prowess as a hitter and for his durability, a trait which earned him his nickname "The Iron Horse". He was an All-Star seven consecutive times, a Triple Crown winner once, an American League (AL) Most Valuable Player twice, and a member of six World Series champion teams. He had a career .340 batting average, .632 slugging average, and a .447 on base average. He hit 493 home runs and had 1,995 runs batted in (RBI). In 1939, he was elected to the Baseball Hall of Fame and was the first MLB player to have his uniform number retired.

Gehrig was diagnosed with amyotrophic lateral sclerosis (ALS) in 1939, a disorder now commonly referred to as Lou Gehrig's disease in North America.