Middlesbrough has impressed at times during its return to the Premier League this season, and now the club looks to bolster its backline as the transfer window closes.
Chambers, 21, has made 58 appearances in the PL with both the Gunners and Southampton, while also earning three caps for England.
Middlesbrough manager Aitor Karanka revaled his excitement over the signing, while also stating that the player addresses a big need on the backline.
“I’m really pleased,” said Karanka. “It’s a position where we’ve been working towards bringing the right player in. We haven’t been in a hurry because Calum was the player we were waiting for, and he’s going to help us a lot.”Follow @MattReedFutbol