Rangers entered administration in February 2012 and were subsequently liquidated. Charles Green, who bought the business and assets of Rangers from the administrator, attempted to transfer the player contracts to a new Rangers company. Whittaker was one of several players to object to this proposal. PFA Scotland had previously commented that players were entitled to become free agents if they objected to the transfer. Whittaker explained himself in a news conference, saying, "I'm 28 and I want to play at the top level for as much as I can. It doesn't look like Rangers will be in the SPL and there's no European football. We owe no loyalty to the new club. There is no history there for us."
Whittaker signed for English Premier League club Norwich City on 30 June 2012, signing a four-year deal. On 20 July, Whittaker received provisional international clearance from FIFA that allowed him to play while arbitration over his move from Rangers continued.
Whittaker suffered an ankle injury during a friendly match against Celtic, which caused him to miss the start of the 2012–13 Premier League season. Two months after receiving his ankle injury, he described it as the worst of his career. He made his competitive debut for Norwich on 31 October, playing at right back in a 2–1 win against Tottenham Hotspur. A few days later, Whittaker made his league debut for the club, playing at right back and stayed on the pitch for 90 minutes, in a 1–0 win over Stoke City. After making his debut, Whittaker said he was pleased to make his debut with a win. The following month, on 8 December 2012, Whittaker scored his first goal in his Premier League career after an assist from Robert Snodgrass in a 4–3 win over Swansea City.