Alles Door Oefening Den Haag, commonly known by the abbreviated name ADO Den Haag, is a Dutch association football club from the city of The Hague. They play in the Eerste Divisie, the second tier of Dutch football, following relegation from the Eredivisie in the 2020–21 season. The club was for a time known as FC Den Haag, with ADO representing the amateur branch of the club. Despite being from one of the traditional three large Dutch cities, it has not been able to match Ajax, Feyenoord or PSV in terms of success in the Eredivisie or in European competition. There is nonetheless a big rivalry with Ajax and Feyenoord. The Dutch words "Alles Door Oefening" translate into Everything Through Practice.

Amsterdamsche Football Club Ajax, also known as AFC Ajax, Ajax Amsterdam, or commonly Ajax, is a Dutch professional football club based in Amsterdam, that plays in the Eredivisie, the top tier in Dutch football. Historically, Ajax is the most successful club in the Netherlands, with 36 Eredivisie titles and 20 KNVB Cups. It has continuously played in the Eredivisie since the league's inception in 1956, and along with Feyenoord and PSV Eindhoven, it is one of the country's "big three" clubs that have dominated that competition.