Harry Hooper was an American professional baseball player who played right field in the early part of the 20th century. He played a total of sixteen seasons in Major League Baseball, primarily for the Boston Red Sox.

Hooper began his career in 1909, when he was signed to the Red Sox by then-owner John I. Taylor. He quickly established himself as a reliable fielder and a consistent hitter, batting over .300 in three of his first four seasons. He was also known for his base running skills, leading the American League in stolen bases four times.

In 1912, Hooper was a key member of the Red Sox team that won the World Series, batting .310 with five home runs and four stolen bases. He also made a key defensive play in the final game, throwing out Ty Cobb trying to steal second base.

Hooper's career included two batting titles and a total of six World Series appearances with the Red Sox. He also became the first player in MLB history to hit a grand slam in a World Series game, in 1916. He was renowned for his hitting and base running, but also for his fielding, leading the American League in putouts five times.

Hooper retired in 1925, after his final season with the Red Sox. He was elected to the Baseball Hall of Fame in 1971, and is considered one of the greatest players of his era. He was also an early pioneer in the use of batting gloves, which he began wearing in 1916.