The 28-year-old joins the Boro after spending five years at Queens Park Rangers, where he clocked up 128 appearances and was club captain up until his contract expiring in June.

The club beat off interest from a host of clubs to capture the out of contract player on a three-year deal.

Grant becomes new manager Neil Warnock’s first signing and he was delighted to be able to complete the move.

“I’ve known Grant for a few years now,” said the Boro boss.

“Everyone knows I’m looking at the spine of the team, and he’s the right fit for what we need.

“Grant is a smashing lad and I’m sure the fans will really take to him.”

An experienced central defender, Grant started his professional career at Brighton before joining Tottenham in the summer of 2012. From there he had loan spells with Swindon, Birmingham, making his debut for the Blues at the Riverside on the opening day of the 2014/15 season, and Blackpool.

Grant joined QPR in the summer of 2015 and was a key member of the squad, making 30 appearances last season.

The defender will meet his new Boro team-mates for the first time next month when pre-season training gets underway at Rockliffe.