Following spells at the likes of Atalanta, Lecce, Fiorentina, Bologna, Espanyol and Roma, Osvaldo moved to the Premier League with Southampton at the start of last season.
The Italy international proved a controversial figure at St Mary's Stadium - fined for his part in a touchline melee at Newcastle United before being suspended for a reported training-ground scrap with team-mate Jose Fonte.
Osvaldo was loaned to Juventus for the second half of the 2013-14 campaign, where he scored once in 11 appearances, and Southampton confirmed on Wednesday that the 28-year-old had joined Inter on a season-long loan, with Saphir Taider moving in the opposite direction.
"It's an honour for me to join a club like Inter," Osvaldo said in a press conference on Thursday. "I'm really happy and I can't wait to get started.
"I'm determined to get back playing as I know I can. I want to prove myself in this shirt.
"When a club like Inter comes calling, I think anyone would jump at the chance.
"This is a chance for me. If I perform well this season I could stay at Inter for many years.
"Targets? To work hard and show what I can do. There's no point talking before the league kicks off."
