However the England international will immediately return to Blues on loan until the end of the 2012/13 season.
The 19-year-old finalised terms on his move to the top flight in Staffordshire this evening with the Potters agreeing to allow Butland to continue his development at St. Andrew’s for the remainder of the campaign.
The Bristolian has always expressed a desire to play first-team football and the highly-rated stopper will continue to do that for Lee Clark’s side this season.
Butland progressed through the Blues Academy system from the age of 14 and, following a successful loan spell at Cheltenham Town, he made his first-team breakthrough this season.
His Blues debut followed an extraordinary summer that saw Butland represent Great Britain at the 2012 London Olympics before becoming England’s youngest ever goalkeeper by winning his first senior cap during a friendly against Italy last August.
Butland could be in line to add to those international honours having been included in Roy Hodgson’s Three Lions squad to face Brazil at Wembley next Wednesday (6 February).