Sam Byram has completed his move to West Ham, signing a four-and-a-half-year deal at Upton Park.
The 22-year-old has joined the London club for an undisclosed fee, having reportedly turned down a switch to Premier League rivals Everton.
Everton were said to have agreed a £3.7million deal to sign the full-back, but he has opted to join Slaven Bilic's side instead.
Bryam, who can play at right-back and on the right side of midfield, joined Leeds at the age of 11 and has since gone on to break into the first team and establish himself as a regular in the starting XI.
He told West Ham's official website: "I'm unbelievably proud and happy to join a club as big as this.
"I'm just looking forward to what the future holds and hopefully I can achieve things with the team going forward.
"It's a childhood dream of mine to play in the Premier League, so to have the chance to get into a team like this and I just want to get my head down, work hard and hopefully get a chance.
"I spoke to the manager and he is one of the main reasons which attracted me to West Ham. I think he's done unbelievably well with his team so far, so I'm really looking forward to working with him and his staff.
"My uncle and my cousin are big West Ham fans and have bought their tickets for the new stadium. My uncle was down here yesterday getting a shirt with my name on the back. It's nice to have them down here and they'll help me settle so I'm looking forward to seeing them.
"I'm also really looking forward to seeing the new stadium in person. That was another big part in me wanting to come here. It's a massive part of the future of the club and I can't wait to see and hopefully play in it."
Byram has made 24 appearances this season, scoring three goals.