Archer moves to St Mary's on a four year contract and admits manager Russell Martin was a key in his choice.
“That was one of the main reasons why I'm here, his playing style, his coaching and trying to improve me as a player,” Archer said. “It's not a bad place to do that in the Premier League with Southampton.
“I just want to keep scoring goals and improve myself as a player, and I don't think there's a better place to do that than with Southampton. I feel fit and ready, raring to go and get out on the pitch.”
Archer is now reunited with several former teammates, including Nathan Wood and Ben Brereton-Diaz.
“I had a good chat with them when I came. I've seen them this morning, they've all got something positive to say, it's nice. Obviously I knew Ben from last year. I had a good chat with him, so it's nice to have.
“Me and Ben, we love to run and get in behind – similar playing style and we can try and do well on the pitch together. Hopefully I can bring that archer celebration out very soon!”