Princeton has a long and storied sports tradition. Today Princeton student-athletes participate in 19 men's and 17 women's varsity sports; more than half take part in either varsity or club athletic competitions.

Princeton is a member of the Ivy League, which began as an athletic conference of eight colleges, requires academic standards for athletes and bans athletic scholarships. In 1945, the Ivy Group Agreement for football was signed by Princeton, Harvard, Yale, Brown, Columbia, Cornell, Dartmouth and the University of Pennsylvania. The Ivy League was formally organized in 1954 and official competition began in the 1956–57 season. The teams routinely win the Ivy League's unofficial all-sports points championship and place among the national Division I leaders in the Director's Club, which measures overall athletic success in NCAA championship competition. Since the formation of the Ivy League more than 50 years ago, Princeton teams have by far the highest number of league championships.

Princeton students have played football since the 1840s, when intramural events in the quadrangle behind Nassau Hall pitted East vs. West colleges, Whig vs. Clio or "A-L" vs. "M-Z." On November 6, 1869, Princeton played Rutgers in the first-ever intercollegiate football game; Rutgers won 6-4, but Princeton won the second match 8-0, and went on to earn the first of almost 30 national football championships. Princeton football was a national powerhouse through the early decades of the 20th century, with no fewer than 50 Princetonians named first-team All-Americans and many making it to the NFL and Hall of Fame and a Heisman Trophy (Richard "Dick" Kazmaier '52 won the award in 1951).

Princeton has had organized baseball teams since 1857, playing its first outside game in 1860 and its first intercollegiate game in 1864.

Princeton played the first-ever ultimate Frisbee game — against Rutgers — on November 6, 1972.

Princeton has also featured prominently in the Olympics, beginning with the first modern Olympic Games in 1896, in Athens, where Robert Garrett Jr., Herbert Jamison, Francis Lane and Albert Tyler, all members of the Class of 1897, participated in track and field and earned two first-place finishes, three second places and one third (medals were not awarded until 1908). Princetonians participated in every subsequent Olympiad with the exception of the 1960 Olympics in Rome; several Princetonians qualified to attend the 1980 Olympics in Moscow, but did not attend due to the U.S. boycott. Princetonians also participated in the Winter Olympics in 1932, 1936, 1948, 1998, 2002, 2006, 2014, 2018 and 2022.