1890 in sports describes the year's events in world sport.
Non-college amateur championships
- 11 October — Western University of Pennsylvania (later renamed the University of Pittsburgh) played its first ever football game in a 38–0 loss to the Allegheny Athletic Association, which was held at Exposition Park.
- 15 November — The Colorado Buffaloes play their first football game against the Denver Athletic Club.
- 22 November — College football is first played in the state of Kansas at the 1890 Kansas vs. Baker football game
- 29 November — The first Army–Navy Game is played. Navy wins 24–0.
- The Football League – Preston North End 33 points, Everton 31, Blackburn Rovers 27, Wolves 25, West Bromwich Albion 25, Accrington FC 24
- FA Cup final – Blackburn Rovers 6–1 The Wednesday at The Oval
- For the 1890–91 Football League season, Stoke FC is expelled and replaced by Sunderland FC who will remain in the top flight continuously until 1958, a record of 68 seasons that only Arsenal's current run (since 1919) has beaten.
- Middlesbrough FC is split by a dispute over whether to turn professional or not. A breakaway group, who favour professionalism, form a new club called Middlesbrough Ironopolis which joins the Football League in 1893 but becomes bankrupt after only one season. Middlesbrough FC eventually turns professional in 1899 and is elected to the Football League at that time.
- Formation of the Union des Sociétés Françaises de Sports Athlétiques (USFSA), the principal governing body of football in France until 1919 when it is superseded by the Fédération Française de Football (FFF).
- Scottish Cup final – Queen's Park 2–1 Vale of Leven (replay following 1–1 draw)
- The Scottish Football League (SFL) is founded as one division of 10 teams. Founder members are Abercorn, Cambuslang, Celtic, Cowlairs, Dumbarton, Hearts, Rangers, St Mirren, Third Lanark and Vale of Leven.
- National League v. American Association – Louisville Colonels (AA) ties Brooklyn Dodgers (NL) three games each.
- 10 July — death by tuberculosis of Paddy Duffy, the reigning World Welterweight Champion. The title remains vacant until 1892.
- The inaugural World Featherweight Champion is Torpedo Billy Murphy of New Zealand who is recognised following his 14th-round knockout of Ike Weir at San Francisco on 13 January. Murphy is defeated by Young Griffo of Australia on 2 September at Sydney. Griffo retains the title until 1892 when he steps up to the lightweight division. The featherweight division is for fighters weighing between 118 and 126 lb, although the limit fluctuates somewhat in the division's early days.
Lineal world champions
- World Heavyweight Championship – John L. Sullivan
- World Middleweight Championship – Jack Nonpareil Dempsey
- World Welterweight Championship – Paddy Duffy → title vacant following death of Paddy Duffy
- World Lightweight Championship – Jack McAuliffe
- World Featherweight Championship – Torpedo Billy Murphy → Young Griffo
- In South Africa, the inaugural Currie Cup is won by Transvaal
- The 1890 English cricket season is the first in which the County Championship is held officially. The champion county is Surrey who win nine out of fourteen games.
- England, captained by W. G. Grace, win The Ashes 2–0. One Test match is abandoned.
- County Championship – Surrey
- Most runs – William Gunn 1,621 @ 34.48 (HS 228)
- Most wickets – George Lohmann 220 @ 13.62 (BB 8–65)
- Wisden Five Great Wicket-Keepers – Jack Blackham, Gregor MacGregor, Dick Pilling, Mordecai Sherwin, Henry Wood
- Grand National – Ilex
- 1,000 Guineas Stakes – Semolina
- 2,000 Guineas Stakes – Surefoot
- The Derby – Sainfoin
- The Oaks – Memoir
- St. Leger Stakes – Memoir
- Queen's Plate – Kitestring
- 4 March 4 — the Montreal Hockey Club defeats the Montreal Victorias 2–1 to retain the 1890 AHAC season title.
- 19 November 19 — the Ottawa City Hockey League is founded to administer ice hockey in the area of Ottawa, Ontario, Canada.
- 27 November 27 — the Ontario Hockey Association is founded to administer ice hockey in Ontario, Canada.
The Boat Race
Home Nations Championship
- Wimbledon Men's Singles Championship – Willoughby Hamilton (GB) defeats William Renshaw (GB) 6–8 6–2 3–6 6–1 6–1
- Wimbledon Women's Singles Championship – Lena Rice (GB) defeats May Jacks (GB) 6–4 6–1
- Polsson, Ken (23 September 2011). "Chronology of Sports". worldtimeline.info. Archived from the original on 4 October 2011.
- "Scottish Cup Past Winners | Scottish Cup | Scottish FA". www.scottishfa.co.uk. Retrieved 5 February 2021.
- Cyber Boxing Zone – Paddy Duffy. Retrieved on 13 November 2009.
- "Cyber Boxing Zone". Archived from the original on 2009-06-03. Retrieved 2009-06-13.
- "Cyber Boxing Zone". Archived from the original on 2009-06-14. Retrieved 2009-06-17.
- "Epsom Derby | History, Winners, & Facts | Britannica". www.britannica.com. Retrieved 29 December 2021.