Southampton have completed the signing of Andrew Davies from Middlesbrough for an undisclosed fee.
Davies had been on loan at St Mary's for the past three months and has now agreed a two-and-a-half year contract with the Championship club.
Saints boss George Burley feels the capture of the 23-year-old is an important signing for the club.
"Andrew is a very talented player and I am delighted he has signed for us," Burley told the club's official website.
"He is young and has a bright future ahead of him. There is no doubt in my mind that he has Premiership quality.
"He has done very well on loan for us. He has shown he is an excellent defender who is strong and competitive and good in the air.
"It is very important for the future of the club that we have been able to get him. It is the key to pushing forward.
"When we signed him on loan, the intention was to make it permanent in January and I am pleased we have been able to do that."
During his Middlesbrough career the former England Under 21 international made 65 appearances for the Premier League side.