Victory seemed assured once George Byers headed in Barry Bannan’s fifth-minute free-kick, and Callum Paterson’s tap-in before the break gave the Owls an insurance policy they never needed to cash in.
Charlton were poor - their only serious effort on target came when Mason Burstow was gifted the chance by an error from Marvin Johnson in the second half - but Wednesday displayed perfect game management, to see the game out.
It was the Owls’ sixth win in seven games and saw them climb into the top-six of League One for the first time since November.
And with just 13 games remaining in the regular season, Darren Moore’s team are starting to gather momentum as they target an instant return to the Championship.
“We are really pleased to get the three points,” said Moore. “It was good to get the early goal. We controlled the game from start to finish. I was delighted to get the second one before half-time.
“I said to the boys at half-time it was about us maintaining our concentration levels. We knew Charlton would have to come out second half and it was all about getting the third goal and not conceding. At best we get the third goal, at worst it finishes 2-0.
“I was really pleased with how we controlled the game and our concentration levels. We didn’t allow Charlton any momentum in the game.”
We did the damage in the first half and it was more about our defensive play off the ball and we didn’t give them anything.
The Owls made three changes from the side which beat Doncaster Rovers last week, Sam Hutchinson back from injury while Paterson and Saido Berahino promoted from the bench after scoring in the South Yorkshire derby.
Wednesday started brightly – three corners in the opening two minutes – and took the lead on five minutes.
Bannan’s curling free-kick found the head of Byers, who flicked the ball into the far corner.
What followed was a scrappy affair, not helped by the Hillsborough pitch – heavily sanded after the recent poor weather – before Bannan tried his luck on 28 minutes, curling a long-range effort just wide.
Paterson went close too with a near-post chance, while Marvin Johnson’s long-range strike was deflected wide for a corner.
The second goal came just before half-time, just reward for a dominant opening 45 minutes.
Johnson escaped his marker down the left flank, and his low cross was turned home by Paterson.
Such was the comfort for the Owls, even defender Jack Hunt attempted an acrobatic overhead kick in front of the Kop.
Burstow spurned a great chance to cut the deficit, after loose play from Johnson in his own half, but he fired straight at Bailey Peacock-Farrell.
Wing-back Johnson nearly scored at the other end, only for a superb block from Chris Gunter to thwart the Owls left wing-back.
Substitute Sylla Sow attempted a lob over stranded goalkeeper Craig MacGillivray, but the ball dropped wide, before Luongo burst through only to be thwarted by the Charlton No 1.