Sheffield Wednesday have beaten off competition from other Championship clubs to sign Adam Reach from Middlesbrough.
Reach, 23, spent last season on loan at Preston North End, and was a key player in the Boro team which lost the Championship playoff final to Norwich in 2014-15.
The left-winger, who has signed a five-year contract at Hillsborough, moved for a substantial undisclosed fee.
"I'm really pleased. It's been a whirlwind day and I went into it not really knowing what was going to happen," he told Wednesday's official website. "I trained with Boro and then as soon as I was told of the interest from Sheffield Wednesday, I wanted to get straight down here.
#DeadlineDay | @AdamReach has completed his move from @Boro to #swfc. Read the full story at https://t.co/Ofdb166N9k pic.twitter.com/rraaKavjnI
- Sheffield Wednesday (@swfc) August 31, 2016
"Everyone knows what the club achieved last season and everyone knows what they want to achieve this season. I want to be part of that."
Wednesday reached the Championship playoff final last season but lost 1-0 to Hull City in the final. The Owls have also sold Marnick Vermijl to Preston North End on deadline day.
Reach, who scored in a 3-1 win for Boro at Hillsborough at the start of last season, joins Steven Fletcher, Jake Kean, Almen Abdi, Daniel Pudil, David Jones, Vincent Sasso and Will Buckley in putting pen to paper at the South Yorkshire club.
He added: "This is a huge club and the next challenge of my career, the time feels right. You try not to get involved in speculation but once I knew Sheffield Wednesday were interested, I knew where I wanted my next move to be.
"This place rocks and I know because I have played here. I can't wait to pull on the shirt and get cracking."