1857 in sports describes the year's events in world sport.
Baseball
National championship
- National Association of Base Ball Players champion – Brooklyn Atlantics
- In May, sixteen base ball clubs from modern New York City convene and revise the rules including replacement of 21 runs by 9 innings. The convention will be known as the first of the National Association of Base Ball Players although there is yet no annual commitment or formal organization.
Boxing
Events
- John Morrissey retains the Championship of America but there is no record of any fights involving him in 1855.
- 10 February — Tom Sayers defeats Aaron Jones in the 85th round at Medway, Kent. Having beaten Harry Poulson the previous year, Sayers is now the main contender for the Championship of England title disputed by William Perry and Tom Paddock.
- 16 June — Sayers defeats Perry after 85 rounds at the Isle of Grain. Sayers claims the title but most backers still recognise Paddock, who does not fight this year. Perry's career ends after his defeat by Sayers. the rugby union club which is now part of Liverpool St Helens F.C. It will merge with St Helens RUFC in the 1980s but still claims to be the world's oldest "open" rugby football club.
Horse racing
England
- Grand National – Emigrant
- 1,000 Guineas Stakes – Imperieuse
- 2,000 Guineas Stakes – Vedette
- The Derby – Blink Bonny
- The Oaks – Blink Bonny
- St. Leger Stakes – Imperieuse
Rowing
The Boat Race
- 4 April — Oxford wins the 14th Oxford and Cambridge Boat Race