Lee, 30, was first linked to Carrow Road six years ago, joining Cardiff City from Rotherham instead. He then joined Ipswich Town before joining Crystal Palace last summer.
The burly hitman will bring power to the Canaries frontline but will have to squeeze into a loanee-heavy squad, which featured Ryan Bertrand, David Mooney, David Carney, Jason Shackell, Adrian Leijer and Alan Gow at the weekend. His arrival could cast doubt over the future of Mooney, who has yet to extend his loan from Reading.