The league's boundaries stretch from Rhigos in the north to Carnetown, Abercynon in the South of the Cynon Valley.

The Aberdare & District Junior League was founded in 1904.

The founder member clubs were: Aberaman Stars, Aberaman Windsors, Aberdare Crescents, Aberdare Excelsiors, Cefnpennar, Cwmbach Lilywhites, Gadlys Rovers, Greenhill Rovers, GWR Rovers and Mardy Albions, and the first champions were Aberdare Crescents.

Also in 1904, the Aberdare Leader Junior Medals competition was founded by the local newspaper, and was won by Aberaman Windsors.

[2] Since 2015, the league has not had junior divisions (under-12 to under-16), with it now being the responsibility of the newly formed Cynon Rhondda Merthyr Junior Football League.