Best completed a deal and signed a three and a half year contract at St James' Park this afternoon.
Speaking to Newcastle's club website, Hughton, who has also taken former City loanee Patrick van Aanholt on loan said: "What people forget is how young Leon is because he's been around for a few years now.
"He was one of a number of young players at Southampton who came through together and showed a lot of promise.
"He is a good age, at 23, and certainly has his best years ahead of him.
"He has a lot of development left in him and we hope to see that here at Newcastle.
"This season has also been his best in terms of goals and he's into double figures.
"I think he will bring more options in attack and I'm delighted to complete the deal."
"He has a lot of development left in him and we hope to see that here at Newcastle.
"This season has also been his best in terms of goals and he's into double figures.
"I think he will bring more options in attack and I'm delighted to complete the deal."