Onomah featured for Wednesday in their Championship match against Stoke at the Hillsborough Stadium on Saturday afternoon.
The 21-year-old midfielder - who joined the Owls on a season-long loan deal from Premier League club Tottenham in the summer transfer window - did not start the match, but the former Aston Villa loanee came on as a substitute midway through the second half.
The England Under-21 international - who earns £30,000 per week as salary, according to Spotrac.com - has taken to Twitter to express his delight at making his debut for Wednesday.
Wednesday played out a 2-2 draw with Stoke at the Hillsborough Stadium in the Championship on Saturday afternoon.
Benik Afobe scored twice for Stoke inside the opening 22 minutes, while Marco Matias and Barry Bannan found the target for Owls thereafter.
Happy to make my debut for @swfc! Good resilience & fight to come back from 2 goals down. Now onto the game on Wednesday !— Joshua Onomah (@Joshuaonomah10) September 15, 2018
Nice moves today Josh, liked the way you were looking for the ball welcome to Sheffield— She-owl7 (@sheowl7) September 15, 2018
That first touch and pas— Jill (@RlJill) September 15, 2018
Looking forward to seeing you play many games for the Owls.— Cheryl (@CherylSwfc) September 15, 2018
Welcome to you. Look forward to seeing what you can do.— Kelly W (@rufterwoof) September 16, 2018
Played well when you came on and drove the team forward. Looking forward to seeing you start and linking up with Bannan, FF and Hooper (when fit).— Jim Tankard (@JimTankard) September 15, 2018
congratulations on first start and well done, good times to come for us all— Stephen Bellamy (@owlertron) September 15, 2018
but blue heart in future please.
Solid debut from the bench today pal, hopefully you will push in and possibly get a start. Got a sneaky feeling you will be in the 1st XI when we play in the play off final again this year— Chris Varley (@ChrisVarley) September 15, 2018