Kroon began his career in Stattena IF. In 1925, he moved to the nearby club Helsingborgs IF where he made 516 appearances and scored 318 goals. Kroon won Allsvenskan five times with the club, and retired from his career in 1942.
He made 35 appearances in the national team (1925–1934) and was a member of the team in 1934 FIFA World Cup. He scored the winning goal (3-2) in the first round against Argentina. Some sources consider him as the first goalscorer in the history of World Cup preliminary competition, when Sweden scored against Estonia 7 minutes into the game on 11 June 1933, in Stockholm. Some other sources consider this goal was scored by Estonian goalkeeper Evald Tipner, thus being an own goal.