However, as part of the agreement Dani Osvaldo moves in the opposite direction on the same terms, leaving Saints with no net gain as they seek to bolster a squad short on numbers.
Taider, a 22-year-old midfielder, played in two of Algeria's matches at the recent World Cup and joined Inter a year ago following a two-season stint at Bologna.
"It's part of our philosophy to bring in talented young players who like to learn and develop themselves, and that's true of Saphir," Southampton manager Ronald Koeman said.
"He can play as a controlled midfielder, but he can also move up around the box and up front.
"That's a good thing for a coach or manager because it brings more possibilities to the players in the team
He brings competition to the squad.
"He can still learn some things, so we will train him and develop him this season.
"Over the course of the year, we will then make a decision about the future of the player."
Dusan Tadic, Graziano Pelle and Ryan Bertrand have already joined the club, with Saints hoping the arrival of Taider will appease fans who are mourning the sales of Rickie Lambert, Luke Shaw, Adam Lallana, Calum Chambers and Dejan Lovren.
Source : PA
Source: PA