George Friend is hoping to help Middlesbrough win promotion to the Premier League after finalising his move from Doncaster Rovers.
The versatile defender has signed a three-year contract to join Boro for an undisclosed fee following Doncaster's relegation from the Championship at the end of last season.
He was also a target for Ipswich Town and Nottingham Forest, but the 24-year-old admits he was swayed by the quality of squad Tony Mowbray has pieced together at The Riverside.
"Middlesbrough finished just outside the play-off places last season and Tony Mowbray is building a really strong squad here," Friend told the club's official website.
"I took that into account when deciding to move here because my ambition is to help this club achieve promotion.
"It has been fairly crucial to make the right choice, and a big attraction was how the manager likes to play football. I've seen what he has done at previous clubs and his teams like to pass the ball. I hope I fit into that category and I can't wait for the season to start.
"The manager has made some quality signings this summer and these are exciting times for Middlesbrough."
Boro boss Mowbray is happy to have added Friend to his squad and is confident the defender will increase the fight for places in his starting line-up.
Mowbray said: "I think George will be a good signing for us. He's a versatile player who can play at centre-half and left-back. He's very athletic and very mobile and has all the attributes you look for in a player.
"He's going to create really good competition to get into our side."