Jackson, who was nominated twice before for the first two parts to his "Lord of the Rings" trilogy, triumphed on the third try with the final installment of the J.R.R. Tolkien epic, Monday's Hollywood Reporter says.
Jackson prevailed during Saturday's awards ceremony over a competitive field of nominees that included Sofia Coppola for "Lost in Translation," Clint Eastwood for "Mystic River," Gary Ross for "Seabiscuit" and Peter Weir for "Master and Commander: The Far Side of the World."
"I am so proud to accept this for making a film that, thanks to J.R.R. Tolkien's book, promotes the values of courage, of friendship and faith," Jackson said upon accepting the award.
Jackson's win makes him a front-runner going into the Oscars. "Return of the King" is nominated for 11 awards, including best director for Jackson.
Only six times since 1949 has the winner of the DGA award failed to win best directing Oscar.
Jackson also won a Golden Globe for best director.