The 28-year-old, who was a free agent having rejected the transfer of his contract to the newco Rangers, enjoyed a successful five years at Ibrox following a transfer from Hibs.
Manager Chris Hughton, making his first signing, told the website: "In Steven we have a player who is very versatile - he can play anywhere across the back four and anywhere across midfield, so there's plenty of versatility there.
"It's probably a good time for him. Sometimes it is time to move on to a different club and go there with a lot of enthusiasm and he has international experience too.
"He has of course been used to playing at a very high level when he was at Rangers and in a lot of big games with a passionate crowd behind him.
"So the stage of the Premier League is certainly one that won't faze him with his experience."
Whittaker, who appeared in Rangers' 2008 UEFA Cup final defeat by Zenit St Petersburg, said: "All of my experience to date has been in Scotland so I am really looking forward to the challenge of playing in the Premier League, I'm very excited about it.
"When I spoke to Chris Hughton I was very impressed with his plans to progress Norwich City and everyone I've spoken to in the game has had nothing but praise for the club and the city of Norwich."
Source: AFP
Source: AFP