Stanley Frank Musial (/ˈmjuːziəl, -ʒəl/; born Stanislaw Franciszek Musial; November 21, 1920 – January 19, 2013), nicknamed "Stan the Man", was an American professional baseball player. Widely considered to be one of the greatest and most consistent hitters in baseball history, Musial spent 22 seasons as an outfielder and first baseman in Major League Baseball (MLB), playing for the St. Louis Cardinals from 1941 to 1944 and from 1946 to 1963. He was inducted into the Baseball Hall of Fame in 1969 in his first year of eligibility.

Musial was born in Donora, Pennsylvania, where he played on the baseball team at Donora High School. Signed to a professional contract by the St. Louis Cardinals as a pitcher in 1938, Musial was converted into an outfielder and made his major league debut in 1941. Noted for his unique batting stance, he quickly established himself as a consistent and productive hitter. In his first full season, 1942, the Cardinals won the World Series. The following year, Musial led the NL in six different offensive categories and earned his first MVP award. He was also named to the NL All-Star squad for the first time; he appeared in every All-Star game in every subsequent season he played. Musial won his second World Series championship in 1944, then missed the 1945 season while serving in the Navy. After completing his military service, Musial returned to baseball in 1946 and resumed his consistent hitting. That year, he earned his second MVP award and his third World Series title. His third MVP award came in 1948, when he finished one home run short of winning baseball's Triple Crown.

Over the next decade, Musial won four more batting crowns, and variously led the NL multiple times in runs, doubles, slugging percentage, total bases, and games played, as well as posting seasonal leads in hits, triples, RBIs, and walks. He batted well over .300 every single year, and was fearsome enough at the plate to lead the NL in intentional walks in five of the 10 seasons through 1958. After struggling offensively in 1959, Musial used a personal trainer to help maintain his productivity until he retired in 1963.

Over the course of his career, Musial batted .331 and set National League (NL) records for career hits (3,630) (1,815 each at home and on the road), runs batted in (1,951), games played (3,026), at bats (10,972), runs scored (1,949) and doubles (725). His 475 career home runs then ranked second in NL history, behind only Mel Ott's total of 511. A seven-time batting champion, he was named the National League's (NL) Most Valuable Player (MVP) three times and was a member of three World Series championship teams. At the time of his retirement, he held or shared 17 major league records and 29 National League records. He also shares the major league record for the most All-Star Games played (24) with Hank Aaron and Willie Mays.

In addition to overseeing personal businesses during and after his playing career, Musial served as the Cardinals' general manager in 1967. The team won the pennant and the 1967 World Series, and Musial then resigned his position. Musial was selected for the Major League Baseball All-Century Team in 1999. In February 2011, President Barack Obama presented Musial with the Presidential Medal of Freedom, the highest civilian award that can be bestowed on a person by the United States government.

Musial was born in Donora, Pennsylvania, as Stanislaw Franciszek Musial (Polish: Stanisław Franciszek Musiał) on November 21, 1920. He was the fifth of the six children (four girls and two boys) of Lukasz Musial (originally Łukasz Musiał; /ˈmuːʃaʊ/) and Maria "Mary" Lancos. His mother was a Czech American born in New York City. His father was a Polish immigrant from Przemyśl who always referred to his son by the Polish nickname Stasiu, pronounced "Stashu". Young Stan frequently played baseball with his brother Ed and other friends during his childhood, and considered Lefty Grove his favorite ballplayer. Musial also learned about baseball from his neighbor Joe Barbao, a former minor league pitcher. When he enrolled in school, his name was formally changed to Stanley Frank Musial.

At age 15, Musial joined the Donora Zincs, a semi-professional team managed by Barbao. In his Zincs debut, he pitched six innings and struck out 13 batters, all of them adults. He played one season on the newly revived Donora High School baseball team, where one of his teammates was Buddy Griffey, father of MLB player Ken Griffey Sr. and grandfather of Ken Griffey Jr. His exploits as a rising player in Pennsylvania earned him the nickname "The Donora Greyhound".

Musial also played basketball and was offered an athletic scholarship to play it at the University of Pittsburgh. Meanwhile, the St. Louis Cardinals had scouted Musial as a pitcher and offered him a professional contract after a 1937 workout with their Class D Penn State League affiliate. Musial's father initially resisted the idea of his son pursuing a baseball career, but he reluctantly gave consent after lobbying by his son and his wife. Musial also credited his school librarian Helen Kloz for pointing out that baseball was his dream and advising him to pursue it professionally. In what was then a common practice, the Cardinals did not file the contract with the baseball commissioner's office until June 1938. This preserved Musial's amateur eligibility, and he was still able to participate in high school sports, leading Donora High School's basketball team to a playoff appearance. He then reported to the Cardinals' Class D affiliate in West Virginia, the Williamson Red Birds.