Ronaldus de Boer is a Dutch former professional footballer who played as a midfielder. He played for the Netherlands national team as well as a host of professional clubs in Europe. He is the twin brother of Frank de Boer. The majority of his success as a football player was with Ajax. He works as the Ajax A1 assistant manager.

The Netherlands national football team has represented the Netherlands in international men's football matches since 1905. The men's national team is controlled by the Royal Dutch Football Association (KNVB), the governing body for football in the Netherlands, which is a part of UEFA, under the jurisdiction of FIFA. Most of the Netherlands home matches are played at the Johan Cruyff Arena, De Kuip, Philips Stadion, and De Grolsch Veste.