Following the example of England two other members of the International Football Association Board (founded 1886) inaugurated leagues in the 1890-91 season.
In Scotland Dumbarton and Rangers were joint champions- they finished the league season level on points and a play-off game at Cathkin Park on 21st May ended in a 2-2 draw.
The giants of 19th century Scottish football, Queen's Park declined to join the League in a stand against illegal professionalism.
In an eventful season Renton were were expelled from the league for professionalism (the result of them playing a match against Edinburgh Saints, who were actually St Bernard's, who had been banned by the Scottish FA for paying players) and Celtic, Third Lanark and Cowlairs were all deducted points for fielding ineligible players.
In Ireland seven of the eight teams who contested the league came from Belfast. The title went to Linfield, who were founded in 1886 in Sandy Row in south Belfast by workers at the Ulster Spinning Company's Linfield Mill. Linfield's record that season was played 14, won 12, drawn 1 , lost 1- goals for 89, goals against 18. Very healthy.