Saints have announced the signing of Lyon defender Dejan Lovren in an £8.5m deal.
The 23-year-old Croatian international has penned a four-year contract and becomes the club's first signing of the summer.
Centre half Lovren, who was linked with a move to St Mary's last week, bolsters the heart of Saints' backline, which was a priority to strengthen during the off-season.
Lovren told Saints' official website: "I’ve spoken a lot with the chairman and the coach, and this is a great project.
"They told me a lot of positive things, and I know the history of the club. It’s a big club and I’m very happy that I can be a part of it.
"After three-and-a-half years in France, it was a dream to play in the Premier League. Now the dream has come true."