The Tri Nations is an annual international rugby union series held between Australia's Wallabies, New Zealand's All Blacks and South Africa's Springboks. The series is played on a home-and-away basis. Originally the three nations played each other twice but that was changed to three times, beginning in 2006. The competition is organized by SANZAR, a consortium formed by the rugby governing bodies of Australia's ARU, New Zealand's NZRFU and South Africa's SARFU.

The first tournament was contested in 1996 and was won by the All Blacks. Since the inception of the Tri Nations series the games played between Australia and New Zealand also determine the winner of the Bledisloe Cup each year.