The 22-year-old has signed a four-year deal at St Mary’s and leaves Villa despite only returning from Sheffield United last month.

The England Under-21 international rejoined Villa after the Blades’ relegation from the Premier League last season triggered a buy-back clause, but they have now decided to sell him again.

Archer said: “I’m really excited to be here. I had a good chat with the gaffer [Russell Martin]. Obviously, he told me everything I needed to hear.

“That was one of the main reasons why I’m here, his playing style, his coaching and trying to improve me as a player. It’s not a bad place to do that in the Premier League with Southampton.

Archer joined Sheffield United for £18m last summer and scored four goals – including one in the 1-1 draw at Villa Park – as the Blades finished bottom of the league.

He had loan spells at Preston and Middlesbrough while at Villa, where he made 14 appearances – although just two starts – in his first spell, scoring four times.

The forward has joined Southampton in time to travel for their Premier League opener at Newcastle on Saturday.

The Saints have signed several players, including Ben Brereton Diaz, Nathan Wood and Ronnie Edwards, after promotion from the Championship last season.