The Scottish striker has arrived on a free transfer from Sunderland.
The move is a massive coup for The Owls as they look to secure promotion to the Premier League next season, after missing out to Hull City in the play-off final last term.
Fletcher was a free transfer after his contract at Sunderland had expired and spent the end of last season out on loan at French giants Marseille. He has cost millions in transfer fees over the years and has played Premier League football for the past seven seasons.
The 29-year-old looks like a fantastic coup for Wednesday, with the idea of him, Gary Hooper and Fernando Forestieri in attack filling Owls fans with real excitement ahead of the 2016-17 Championship campaign.
A sometimes divisive character there is no doubt how the Wednesday fans feel about the move on Twitter.
The overwhelming majority are ecstatic at the signing and are hopeful that he can help fire the club one better than last season.
Here is some of the best reaction…
Forestieri, Fletcher, McCormack & Hooper (& Joao)... 50+ goals a season there! #swfc— Alex Serrano (@adserrano1) July 1, 2016
From Gary Taylor-Fletcher to Steven Fletcher— Grant Roberts (@GrantRoberts_91) July 1, 2016
How times have changed. #swfc
Can see the fit with Fletcher even more than McCormack tbh. Not to say wouldn't want both. Line leader. A type needed. Good record. #swfc— Alan Biggs (@AlanBiggs1) July 1, 2016
Four year contract for Steven Fletcher at #SWFC so a big commitment.— Rob Staton (@robstaton) July 1, 2016
Fletcher is a great free signing! Twice the player nuhiu is. Happy with that #swfc— Jordan Groom (@groomSWFC) July 1, 2016
Delighted with Fletcher should give Hooper someone to play off plus he's also a massive upgrade on Nuhiu #swfc— johnny (@johnny_swfc) July 1, 2016
Well pleased with Fletcher signing. Been there and done it! #swfc— Dave Harrington (@dHarrington16) July 1, 2016
Signing Steven Fletcher must send out a massive message ! We are back ! #swfc— Ashley Ogden (@Ashley_Ogden) July 1, 2016