The 24-year-old, who finished top scorer in Italy's top flight in 2013/14, has signed a five-year contract with the Westphalians after helping Torino qualify for the UEFA Europa League last season.
“We’re getting a flexible and dynamic striker who established himself in one of Europe’s top leagues in impressive fashion,” said Dortmund sporting director Michael Zorc. “His outstanding qualities fit perfectly with the profile required by Borussia Dortmund."
With 22 league goals 33 league appearances, Immobile helped fire the Granata to seventh place in Serie A, earning him a call-up from Cesare Prandelli to the Italy squad for this summer's FIFA World Cup in Brazil. Having sought advice from SV Werder Bremen full-back Luca Caldirola and Bayer 04 Leverkusen's Giulio Donati - both former team-mates of his at under-21 level - Immobile recently reaffirmed his desire to move to Dortmund.
"Borussia Dortmund are a huge club and the idea of replacing [Robert] Lewandowski really appeals to me," the Italian said at a press conference. "I've spoken to Caldirola and Donati and they've told me that the Bundesliga's a fantastic league – one of the best in the world."
Immobile rose to prominence as part of Pescara Calcio's Serie B-winning team in 2012, earning a move to Genoa CFC, although Serie A champions Juventus acquired half of his registration with a view to signing him fully in the future. He spent last season with Torino, who secured the other half of the player's registration from Genoa.
The forward has scored a total of 27 goals in the Italian top flight and 30 in the second Italian division. He made his Italy debut in a 1-0 defeat to Spain earlier this year.