Joe Aribo moves to St. Mary’s after three-season stint at Rangers during which he won Scottish Premiership and Scottish Cup titles.
He also scored in last season’s Europa League final defeat to Frankfurt.
The 25-year-old Nigeria international moves to St. Mary’s after three successful seasons at Ibrox, where he scored 26 goals in 149 appearances and won the Scottish Premiership and Scottish Cup.
Southampton manager Ralph Hasenhuttl said: “Joe is a player with many qualities to his game, and we are very excited to welcome him to the squad”.
Aribo took to social media to thank Rangers Football Club and their fans for their support during his time in Glasgow.
“It’s an amazing feeling, a dream come true. This is where I’ve wanted to be”, Joe said.