31 March — the Intercollegiate Athletic Association of the United States (IAAUS) is established to set rules for amateur sports in the United States, including revisions to American football rules that legalise the forward pass. The IAAUS later became the National Collegiate Athletic Association (NCAA) in 1910.
24 November — the Canton Bulldogs-Massillon Tigers Betting Scandal effectively ends the first era of major professional football. All three of the top three teams in the nation will fall by the wayside by 1907.
The Australasian Football Council is established in November to serve as the top-level governing body for Australian rules football in Australia and New Zealand.
Due to the unbalanced nature of the MRFU, each team was awarded different amounts of points for a win, determined by a formula of 30 points divided by number of scheduled games.
George Hirst of Yorkshire and England creates a unique record as the only player to score 2000 runs and take 200 wickets in the same season: 2385 runs and 208 wickets.
March — Ottawa defeats Smiths Falls, Ontario two games to none in another Stanley Cup challenge.
March — Ottawa and Montreal Wanderers tie for first place in the ECAHA league's regular season with 9–1 records. The two clubs hold a playoff to determine the ECAHA and Stanley Cup champion. The Wanderers win the series for their first Stanley Cup win, defeating the Silver Seven in a two-game total-goals series.
Rules of rugby league are changed so that the number of players in a team is reduced from 15 to 13,[6] and following tackles the play-the-ball is introduced in place of rucks and mauls.[7]