Hooper struck twice in the first half and Kieran Lee added a stunning third late on to lift the home crowd following back-to-back defeats at the hands of Sheffield United and Birmingham.
It was Leeds who made the brighter start to the game with Kalvin Phillips heading wide and Samuel Saiz shooting off-target from the edge of the area.
Wednesday’s first chance fell to Ross Wallace who saw his shot blocked following a promising build-up. Leeds threatened again with Ezgjan Alioski heading into the side-netting after meeting a cross from Saiz.
The hosts dominated for the rest of the half and took control of the game with two goals. Wallace’s free-kick was headed down by Tom Lees and Hooper (25) provided the finishing touch from close range.
Lee was unfortunate to have an effort ruled out with television replays showing he should not have been given offside.
Hooper then had a shot deflected wide and Steven Fletcher missed a golden chance, somehow heading wide from point-blank range after meeting Wallace’s cross.
The second goal came when Liam Palmer delivered a deep cross which was headed back across the face of goal by Fletcher and Hooper (41) headed in off the inside of a post.
The second half was only a few minutes old when Leeds went desperately close to reducing the arrears.
Alioski’s low cross from the left was missed by a couple of defenders and the ball found its way to Pierre-Michel Lasogga whose shot came back off Joe Wildsmith’s right-hand post.
Barry Bannan clipped a shot wide from 20 yards before setting up another chance for Hooper when his through-ball picked out the striker’s run into the area, but Leeds goalkeeper Felix Wiedwald came to his side’s rescue with an important block.
The visitors then threatened on a couple of occasions in quick succession.
Pontus Jansson’s header was cleared off the line by Lee and Saiz’s curling effort was just wide of Wildsmith’s left-hand post.
Leeds boss Thomas Christiansen was forced to make a change when Jansson was taken off on a stretcher and replaced by Stuart Dallas.
Leeds went close again when Pablo Hernandez slipped the ball through to Saiz who was through on goal and his shot was well saved by Wildsmith.
Wallace’s shot from distance was saved by Wiedwald and Bannan saw his effort strike a post before Lee (82) added a third, beating the goalkeeper with a fine shot from just outside the ‘D’ after receiving Eunan O’Kane’s attempted clearance.
Sheffield Wednesday: Wildsmith, Hunt (Palmer 39), Lees, van Aken, Reach, Wallace, Lee, Jones, Bannan (Butterfield 87), Hooper, Fletcher (Rhodes 90). Subs Not Used: Nuhiu, Lucas Joao, Dawson, Pudil.
Leeds United: Wiedwald, Ayling, Pennington, Jansson (Dallas 71), Berardi, O’Kane, Phillips, Roofe (Hernandez 62), Samuel, Alioski (Sacko 62), Lasogga. Subs Not Used: Lonergan, Grot, Vieira, Shaughnessy.
Referee: Andrew Madley (West Yorkshire).