At the end of each season, the team that finishes in first place in the Premier division is crowned league champions.

The League was founded 4 July 1923 at a meeting of fourteen clubs at the Clarence Place Hall, Donegall Square East, Belfast, initially as a league for teams from public bodies, private associations, schools and firms.

It was affiliated to the Irish Football Association (IFA) as a junior league in August.

The first season was 1923/24 and by the time the first fixtures were played on 22 September, there were 16 member clubs.

were tied at the top of the table, but the Co-operative won a play-off to be crowned the first Amateur League champions.

A knock-out competition – the Clarence Cup – was also inaugurated in the first season, and the first winners were C.P.A., who beat the Co-operative 2–1 in a replay after a 0–0 draw.

In 1932, the League played its first representative match outside Northern Ireland: a 3–3 draw against the Scottish Juvenile FA at Celtic Park, Glasgow.

During the next few years, the League gained intermediate status, and a junior-status second division was added in 1926.

In 1932–1933, the League's strength was demonstrated when Dunville's became the first Amateur League team to win the Irish Intermediate Cup, and in 1938–1939 when Sirocco Works won the Steel & Sons Cup.

In the 1936–1937 season, a new competition was introduced: the Border Regiment Cup (commonly the Border Cup), which was to become the perhaps League's most prestigious trophy as it established a traditional Christmas final.

The first winners were Sirocco Works, who beat Whitehouse Recreation Club 4–0 in the final.

In 1963, it was decided that the Border Cup should be confined to teams in the First Division, and a new knock-out competition – the Cochrane Corry Cup – was instituted for the Second Division teams.

The Clarence Cup is a knock-out competition for all clubs (encompassing both the First and Second Divisions).