UEFA Cup 1999–2000 – Galatasaray won 4-1 on penalties, in the final against Arsenal, after a 0-0 draw at the end of the match. This was the first European title won by a Turkish team.
July 15 – Essendon becomes the first club to win its first nineteen games when it beats Hawthorn 25.15 (165) to 13.4 (82). This beats Collingwood's perfect home-and-away season of eighteen games from 1929.
August 5 – Essendon become the first AFL team to win 21 of 22 games in a VFL/AFL home-and-away season, losing only to the Western Bulldogs in its second last game
European basketball enters a new era with the creation of the Euroleague Basketball (company). This leads to a rift with FIBA Europe and the creation of two separate continent-wide competitions for the 2000–01 season—the SuproLeague, operated by FIBA Europe, and Euroleague Basketball's Euroleague.
August 12 – Evander Holyfield defeats John Ruiz by decision in 12 rounds to regain the WBA's world Heavyweight title, becoming the first boxer to win the world Heavyweight title four times.
The Ring named Félix Trinidad the "Fighter of the Year 2000". Eric Morales won a 12-round points victory over Marco Antonio Barrera, for the unified WBC and WBO 122 Pound Titles, in The Ring's "Fight of The Year 2000".
U.S. Open – Tiger Woods wins by 15 shots, a record for all majors, with a U.S. Open to–par record score of –12.
British Open – Tiger Woods becomes the fifth golfer in history to achieve the modern "career grand slam", and sets the to–par record for all majors (–19).
PGA Championship – Tiger Woods becomes the first golfer since Ben Hogan in 1953 to win three majors in a calendar year. He ties the to–par record for the PGA (–18) with Bob May, and wins in a playoff.
The event was originally scheduled to have a title fight between Kevin Randleman and Pedro Rizzo. However this postponed due to a concussion Randleman suffered before the fight. This event featured, Dan Severn as a referee for the preliminary bouts.
Mark Coleman becomes the Pride 2000 openweight Grand Prix champion. The event featured a highly anticipated match between Royce Gracie against Kazushi Sakuraba.
UFC rule change, New Jersey SACB becomes the first state to regulate MMA in the USA. Uses newly written Unified Rules of Mixed Martial Arts. This event held the first and only UFC super heavyweight bout.
March 18 – Jenny Thompson again betters her own world record in the women's 100 m butterfly (short course), this time in Athens, Greece, from 56:80 to 56:56.
June 16 – At the Russian National Swimming Championships in Moscow, Alexander Popov betters the ten-year-old world record (21.81) in the 50m freestyle (long course), swam by USA's Tom Jager in 1990 – 21.64.
