The Magpies forward bagged his third goal in two games to seal the win for the home side, who survived a few scares and missed from the spot en route to victory over the Canaries
The visitors started the contest well and had a number of chances early on, with Robert Snodgrass' effort cleared off the line by the home defence.
But Newcastle's impressive midfield play, particularly through Hatem Ben Arfa, allowed them to overpower their opponents and they survived a few scares to hold out for all three points despite Papiss Cisse's missed penalty.
Norwich went into the game having won just one of their last nine games but despite the pressure on Chris Hughton, the home crowd welcomed back their former manager with a warm reception.
And it was the Canaries who started the game the brighter of the two sides, looking to use their wide players to expose the Newcastle defence.
They suffered a blow after just seven minutes, though, when Sebastien Bassong, playing against his former club, was forced off after suffering a hamstring injury. His replacement, ex-Sunderland defender Michael Turner, was not received so favourably by the Newcastle supporters.
The first chance of the game resulted in the first goal and came against the run of play as the home side found the back of the net at the end of their first real attack.
Ben Arfa cut in from the right after being given too much space before playing a delightful chipped pass through the middle for Ba, who coolly slotted the ball past the advancing Ruddy.
The former Marseille star almost turned from provider to goalscorer after 22 minutes when he was inches away from latching on to a pass, but missed the ball as he tried to lob Ruddy.
Norwich remained a threat on the break, though, and soon produced another chance. A swift Canaries counter-attack down the left flank saw Andrew Surman's cross met strongly by Snodgrass, whose header beat goalkeeper Steve Harper but not Mike Williamson, with the defender hacking the ball off the line.
Newcastle continued to look the more likely to score, however, and on 30 minutes, the Norwich defence was enduring trouble of its own. Turner stopped Williamson from capitalising on Steven Taylor's header.
Before half-time there already looked to be a clear frontrunner for man of the match. More fantastic play from Ben Arfa saw him run past Surman before slipping a precise pass into the path of Ba, but the striker couldn't connect, allowing Ruddy to pick up the pieces.
With the visitors looking to see the game out until the break, clumsy defending by Turner gave Newcastle the chance to double their lead. The Norwich centre-back barged into Williamson in the box, making the referee's decision an easy one.
Out-of-sorts striker Cisse stepped up to take the spot-kick but blazed over, leaving his side with a narrow lead going into the second period.
Norwich began the second half as they had started the first. Almost immediately, Surman should have levelled the scores but was foiled by Harper after Wes Hoolahan had threaded a pass through the Newcastle defence.
Ben Arfa also carried on where he left off, though, cutting inside and firing a low effort which was well saved by Ruddy on 56 minutes.
Both sides continued to slug it out in midfield without creating many clear cut opportunities, with the Newcastle backline looking solid.
The match ended in a scrappy fashion as Norwich continued to press, with players from both sides receiving yellow cards for respective poor challenges.