The 21-year-old moves to the Cardiff City Stadium on a four-year deal, having completed his medical on Wednesday. 

Caulker made 28 appearances under Andre Villas-Boas last season after spending time on loan at Yeovil, Bristol City and Swansea City in previous campaigns. 

"First and foremost I want to say how happy I am to have signed with Cardiff City Football Club. I’m delighted to be here and excited for this fresh challenge," the England international told Cardiff's official website.

"I spoke to the gaffer (Malky Mackay) yesterday, liked what he had to say and am excited about the plans he has for the football club.

"You get the sense of excitement from everybody at the club in the build-up to the season’s kick-off at West Ham and I’m really looking forward to being part of it.

"I thank Tottenham for everything they’ve done for me, having been there since I was a kid. But I’m here to back myself up now and show what I can do. This is a fresh start, a new chapter and I’m here to kick on."

Caulker will join his new team-mates for training on Thursday and could feature in the club's friendly with Chievo on Saturday. 

Cardiff had previously broken their club record for a player this close-season with the transfer of Andreas Cornelius from FC Copenhagen.