The 1979–80 Princeton Tigers men's basketball team represented Princeton University in intercollegiate college basketball during the 1979–80 NCAA Division I men's basketball season. The head coach was Pete Carril and the team captain was John W. Rogers, Jr.^[2] The team played its home games in the Jadwin Gymnasium on the University campus in Princeton, New Jersey. The team was the co-champion of the Ivy League, but lost a one-game playoff and failed to earn an invitation to either the 1980 NCAA Men's Division I Basketball Tournament or the 1980 National Invitation Tournament.^[3]

The team played a schedule that included eventual national champion Louisville, other members of the 48-team NCAA tournament field such as #3 seed St. John's, #4 seed Duke and #8 Villanova as well as the Big Ten Conference's Michigan State and the Big East Conference's Seton Hall.^[2][4] The team recovered from a slow start in which it lost its first five and eleven of its first thirteen games to post a 15–15 overall record and an 11–4 conference record.^[2] After splitting the regular season series one win apiece on home game victories and finishing tied with identical 11–3 conference records, Princeton and Penn Penn faced each other in a March 4, 1980, one-game Ivy League playoff game. Princeton lost the game which was held at the Kirby Sports Center at Lafayette College in Easton, Pennsylvania, by a 50–49 margin, thus giving Penn the Ivy League Championship and an invitation to the NCAA Men's Division I Basketball Tournament. Princeton would avenge this loss the following year when the two teams finished tied for the conference regular season title again.^[2][3][5] The team was led by first team All-Ivy League selection Randy Melville.^[6]