Variety reports that Jackson will star in the film, which is an adaptation of the non-fiction novel by Ron Hall, Denver Moore and Lynn Vincent.
The screenplay was adapted by father-son duo Roderick and Bruce Taylor, who penned the script for The Brave One.
Jackson will play Denver Moore, a former prisoner who is homeless and has an unlikely friendship with Ron Hall, an art dealer in Dallas.
Samuel L. Jackson is currently filming The Other Guys with Will Ferrell, Mark Wahlberg and Dwayne Johnson. The film hits theatres on August 6, 2010. The actor will also star in Iron Man 2, opening May 7.