It was initially founded in 1877 as a rugby club, but later switched codes to association football.

It is listed as a rugby club in Richard M. Peter's Irish Football Annual 1880 and during the 1879–80 season it played 24 games, taking on, among others, local rivals North of Ireland and Queen's College, Belfast.

[2] On October 24, 1878, the club hosted a demonstration game between two Scottish association football teams, Queen's Park and Caledonian.

This game is recognised as the earliest organised association football match played in Ireland.

[3] Ulster duly played a game in April 1879 to Association rules against Queen's College at Ormeau Road, the sides drawing 3–3, Ulster's goals coming from a scrimmage, C. Thompson, and A. Murray;[4] but otherwise the club continued playing rugby, before switching to association football for the 1882–83 season.