This depends on the season you are referring to.
If you are referring to the 1945-1946 season it was: Haarlem
If you are referring to the 1946-1947 season it was: Ajax
The team that won the Dutch league in 1946 was HFC Haarlem.
Feyenoord
Heracles
Twente
RCH
Feyenoord
Ajax
Ajax
Ajax
Feyenoord
Ajax
Feyenoord