Marcus Tudgay's sixth goal in five games inspired Wednesday to a deserved win as the visitors celebrated Brian Laws' first game in charge in style.
Tudgay steered home the opener from Wade Small's cross after sparking an incisive break from his own half.
Alan Lee should have drawn Town level from close range on the half hour before Matthew Richards also missed.
And they paid for their profligacy when Madjid Bougherra headed his first Owls goal from Kenny Lunt's centre.
Ipswich boss Jim Magilton:
"We started the game very bright and passed the ball very well and looked
"We then got back into the game and had two great chances and if we had taken them it could have been different.
"What is worrying is that we did not have people taking responsibility when it really mattered."
Sheffield Wednesday boss Brian Laws:
"Any manager will tell you when he takes over at a club his first points in the bag are the most important.
"We allowed Ipswich some good chances then we rode our luck and in the second half we limited them to half chances."
Laws added: "The second goal was always going to be key and it was a magnificent set-play."
Ipswich: Supple, Wilnis, De Vos, Bruce, Harding (Naylor 84), Roberts, Legwinski, Noble (Currie 64), Richards, Lee, Haynes (Macken 24).
Subs Not Used: Drobny, Peters.
Booked: Lee, Currie.
Sheff Wed: Crossley, Simek, Bullen, Bougherra, Hills, Small (Whelan 81), Lunt, Folly, Brunt (O'Brien 72), Tudgay, Burton (MacLean 89).
Subs Not Used: Adamson, Coughlan.
Booked: Hills, Small.
Goals: Tudgay 11, Bougherra 82.
Ref: K Stroud (Hampshire).