The former Chelsea trainee spent part of last season on loan with the Owls, scoring seven goals in 19 appearances.
Ugbo, 25, returns to Hillsborough having helped Wednesday maintain their Championship status last term.
He scored six of his goals in five games across February and March as the club transformed their form under boss Danny Rohl to stay up after a torrid start to the campaign.
Having begun his career with Chelsea, Ugbo had loan spells with Barnsley, MK Dons, Scunthorpe, Roda JC and Cercle Brugge before joining Belgian side Genk in 2021.
He later joined Troyes after a loan spell there, before spending time on loan with Cardiff City and Wednesday.
Danny Rohl has welcome a horde of new players to Hillsborough and he takes his new-look side out for the first time against Wayne Rooney’s Plymouth Argyle on Sunday.
And head of their opening game of the 2024/25 Championship season, Sheffield Wednesday have re-signed Ike Ugbo from Troyes.
The Canadian international joins on a permanent deal, with Sheffield Wednesday paying £3million for Ugbo who had plenty of suitors this summer.
Owls fans have been calling for Ugbo’s return all summer long.
The 25-year-old impressed last season scoring seven goals in 18 Championship outings for Wednesday, with his goals playing a huge part in the Owls’ eventual 20th place finish in the Championship.
Ugbo then spoke to the press on Thursday evening, after he was unveiled as a new Owls player, and he discussed the Sheffield Wednesday fans’ love towards him.