The 1915 Detroit Tigers won a club-record 100 games and narrowly lost the American League pennant to the Boston Red Sox, who won 101 games. Though four other Tigers teams have won 100 games, only the 1934 Tigers had a better winning percentage. The 1915 Detroit Tigers team is remembered for its all-star outfield of Ty Cobb, Sam Crawford, and Bobby Veach—who finished #1, #2, and #3 in the American League in both runs batted in and total bases. Baseball historian Bill James ranks the Tigers' 1915 outfield as the best in major league history.

The 1915 Boston Red Sox season was the 15th season in the franchise's Major League Baseball history. The Red Sox finished first in the American League (AL) with a record of 101 wins and 50 losses.