Searchlight will handle marketing and distribution of the film, which is set to receive its world premiere in Toronto and will open in North America on November 28.
Searchlight has worked with Boyle on a number of titles including 28 Days Later, Sunshine, Millions and A Life Less Ordinary.
Slumdog Millionaire charts the fortunes of a teenage boy from the Mumbai slums who is poised to win the main prize on India's Who Wants To Be A Millionaire' Over the course of events his true motives for winning the money reveal themselves.
Simon Beaufoy adapted the screenplay and the film stars Dev Patel, Madhur Mittal, Freida Pinto, Anil Kapoor and Irrfan Khan.
'With the recent additions to our slate, it became impossible for us to release Slumdog Millionaire in this calendar year,' Warner Bros Pictures Group president Jeff Robinov said. 'We're very proud of Danny and the movie, and we are pleased to partner with Fox Searchlight to release the film on November 28, 2008.'
Searchlight president Peter Rice called Boyle's film a 'tour de force of film-making that hits you both viscerally and emotionally at every twist and turn,' adding: 'Searchlight is pleased to able to work with Warner Bros on such a unique and extraordinary film.'
Fox Searchlight's vice president of business affairs Megan O'Brien and executive vice president of worldwide acquisitions Tony Safford brokered the deal with Warner Bros senior vice president of business affairs Jun Oh.
The project was initiated at Film4 which co-developed and co-financed the film with UK production company Celador Films. Celador's Christian Colson produced and Film4 chief Tessa Ross and Celador chairman Paul Smith served as executive producers.