Within his first year at HIK, Madsen made his debut for the Danish national team in October 1958. He was not selected for the 1960 Summer Olympics, but became a mainstay in the team following that tournament. He was eventually named team captain, and scored six goals in three games against the Luxembourg national football team to help Denmark qualify for the 1964 European Nations' Cup. He captained Denmark to a 4th-place finish in the final tournament. That year, Ole Madsen was the first Danish player ever to receive votes in the European "Footballer of the Year" poll, getting one point and a shared 19th place. He was subsequently named 1964 Danish "Player of the Year".