The Black Diamond Football League (BDAFL) is situated on the east coast of Australia in the state of New South Wales. It is north of Sydney and covers an area of more than 150 lineal kilometres from Terrigal Avoca in the South to Nelson Bay in the north. The Muswellbrook Club is 70 minutes drive west of Newcastle.
It was formed at the end of the 1999 season with a combination of clubs from the Central Coast and Newcastle Football Leagues.
The league comprises 13 clubs. Four of the clubs are Upper Hunter based, four in the Newcastle area whilst another five are on the Central Coast. The most northern club in the league is Nelson Bay, Muswellbrook is the most Western and the most southern is Gosford.
In 2016 the competition structure will be composed of six teams in Black Diamond Cup (premier Division), ten in 1st Division and eleven in 2nd Division. These numbers vary from year to year depending on the strength of the respective clubs.
In 2015, the BDAFL formed a women's competition consisting of six teams and in 2016 this competition has been increased to ten teams.
The leadingship trophy in the league is the Black Diamond Cup which was first played for in 1888 and won by the Wallsend Club. The trophy is said to be the oldest Australian sporting trophy still being contested even outdates cricket's Sheffield Shield and is housed in the Newcastle Museum.
The League has an Umpires Association and both the Central Coast and Newcastle have junior competitions. This group creates a region which in total fields 131 teams and had 2875 registered players plus a further 580 registered club Auskick (aged 5-9) participants.
The BDAFL is administered by an independent Board of Management who oversee all aspects of the competition. The day to day activities are managed by a part-time Football Operations Manager.
The league is regarded to be one of the strongest leagues, both on and off the field in NSW/ACT.