From the formation of Basketball Ireland as the Amateur Basketball Association of Ireland in 1947 until 1979, the Irish Basketball Championship was organized on a Club and County basis, with Provincial Championships preceeding the All-Ireland Championships. from 1980 onwards with the formation of the National Basketball League, the All-Ireland Championship and Regional Championship was reserved for Underage Competitions.

All-Ireland Underage Club Cups and Championships

Underage Basketball Championships have been held in Ireland since the time of the Amateur Basketball Association of Ireland (1947-1979) – then known as Minor Championships, they were based on the GAA system of County and Club Championships, with Provincial Championships preceeding the All-Ireland Championships.

After the ABAI was renamed the Irish Basketball Association in 1980 there was widespread restructuring within Irish Basketball, with the counties replaced by Area Boards, and a National League based on Clubs replacing the All-Ireland County and Club Championships. With this there were only Area Board Leagues for Underage grades and son a Playoff system was introduced for the winners of each. The Under 19 Regional Championships were played from the 1980s to early 2000s when again the Regional Championships were replaced by the All-Ireland Club Cups after the rebranding of the IBA as Basketball Ireland.

Amateur Basketball Association of Ireland 1947-1979

The Amateur Basketball Association of Ireland (now Basketball Ireland) was the organisation in charge of running Basketball in Ireland from 1947 to 1979 when it changed its name to the Irish Basketball Association. From 1953 to 1973 it was organised on a Club and County basis like the Gaelic Athletic Association.

The All-Ireland Blitz from 1953 to 1964 was the Club Championship, held on a Blitz basis over the course of a weekend in one venue. It was replaced by the National Basketball Cup, in which the top 16 teams from the four provinces played in four groups of four over the course of a year with semi-finals and final. In 1973 a National League based on clubs replaced the All-Ireland County Championships and National Basketball Cup.