Jamie Vardy has scored three league goals since the turn of the year
Vardy's double ensured the Foxes ended their own seven-game winless run in all competitions and sees them move up to 10th in the table.
It was no more than Brendan Rodgers' side deserved as they dominated possession, although they struggled to make a breakthrough until Vardy's opener, which deflected off Norwich defender Grant Hanley before looping over visiting goalkeeper Angus Gunn.
Harvey Barnes, who created Vardy's first, also supplied the second for the 35-year-old, who timed his run to perfection before firing into the top left corner.
As Leicester moved through the gears, James Maddison blasted an effort into the roof of the net against his former employers, with Gunn unfortunate to see the ball into his path after failing to collect Kiernan Dewsbury-Hall's cross.
Dean Smith's side offered plenty of resistance until falling behind and arguably had the best chance before Vardy broke the deadlock, with Teemu Pukki first-half effort against the post.
However, once they fell behind they wilted and have now conceded 78 goals this term - their worst defensive performance in a top-flight season.
It has been a largely joyless season for Norwich supporters who, apart from one fleeting week, have seen their side rooted in the bottom three for all the campaign.
While this was a marked improvement on Sunday's 4-0 home defeat by West Ham, like so many other performances this season it followed a narrative of what might have been - with Smith able to point to the huge deflection that saw them fall behind and several wasted opportunities at the other end.
Having repelled a brief Leicester flurry, Dimitris Giannoulis, Pukki and 19-year-old winger Tony Springett, making his first start for the Canaries, all had chances to put the visitors in front but were denied by excellent goalkeeping from Kasper Schmeichel.
However, they have only scored 22 league goals all season, and although Pukki hit the post, they failed to register a shot on target after the break.
"I thought we were as good as them in terms of chances created in the first half but when the first goal goes in, we could not chase the game," Smith said.
"We know we are going to come up against teams with more possession and when we concede first, we suffer. We showed some good stuff in the first half but Jamie Vardy's movement for his two goals was exceptional and that is what you are up against at this level."
Having started the season looking to build upon their FA Cup success of last term, Rodgers' side began the evening closer to the relegation zone than the European places, which are now out of reach.
But had Vardy not spent large chunks of the season nursing injuries, their end-of-season prospects may have been significantly enhanced.
"He [Vardy] was outstanding tonight, his physicality, his running and pressing," said Rodgers. "The second goal was classic really. We worked it really well and Jamie does what he does."
With the veteran forward, Maddison and Barnes restored to the starting XI, it felt as if normal service had resumed after a sequence of poor results.
Vardy was a constant threat and had already tested Gunn after ghosting into the left channel before opening the scoring.
His enduring quality was evident with his emphatic second and he had more shots and more touches in the opposition penalty area than any other player.
-- Courtesy of BBC Sport