Connacht League and Wartime (1936 to 1945)

At the start of the 1936–1937 season, a Connacht Badminton League was established by clubs across the province. In its inaugural year, four Mayo clubs—Ballina, Ballinrobe, Castlebar and Hollymount joined the league. The remaining clubs in the county continued to engage in challenge matches. As interest in competition grew, individual tournaments also began to appear, with Swinford Badminton Club hosting one in 1937.

Recognising the increasing popularity of the sport in the region, the Badminton Union of Ireland (now Badminton Ireland) established a dedicated branch for the area in 1938. The new organisation, known as the Western Branch (Connacht Branch), was created to support the development of badminton in Connacht and assumed responsibility for overseeing and managing the Connacht Badminton League.

During this period, three more clubs emerged in Mayo: Kiltimagh, Foxford and Kilmoremoy. Mayo teams remained active in the Connacht League over the following years, with Hollymount finishing as runners-up in 1939, followed by Ballina in 1941.

In early 1942, the Connacht Branch made the decision to establish a dedicated league within County Mayo. This move was likely influenced by the strain World War II was placing on the region. This became evident when teams were given the option to play for double points, with a single match counting as two if both teams agreed, to ensure all league fixtures could be fulfilled. Teams were divided into two groups: Group One included Ballina, Foxford and Swinford. Group Two consisted of Castlebar, Westport, Claremorris and St. Patrick’s (Westport).

The league final took place on March 30, 1942, in the Parochial Hall, Ballina, where Castlebar defeated Ballina 7–1. Castlebar was awarded the Mayo Cup, marking its first presentation. The cup would not appear again for another seventeen years.

Between 1943 and 1945, badminton activity in the county declined significantly due to the deepening effects of World War II. A shortage of rackets and, most critically, shuttlecocks, combined with rising costs, forced many clubs to close. The inability to source affordable shuttlecocks made it difficult for clubs to continue offering matches and training for their members.