Parliament voted to create the break eight years ago but only now is the legislation coming into being.
It means the 1,250 clergy in the Church of Norway will no longer be employed by the government and the Church will become an independent business.
The bill put together to create the split says the Church of Norway will remain the national church and will be supported by the state.
Some in Norway wanted the split to be further defined but Jens-Petter Johnsen from the Church's National Council said: "We are facing the biggest organisational change of the church since the Reformation.
"The changes will create a clear separation between church and state."
Around 80 per cent of Norway identifies as Christian but only a small number regularly attend church services.