Mattingly's job was widely considered in jeopardy when the Dodgers and their $217 million payroll got off to a 17-25 start and were seven games out of first place in the National League West.
But they rebounded to go 92-70 en route to claiming the division title, advancing to the NL Championship Series before falling to the St. Louis Cardinals.
Terms of Mattingly's deal weren't announced, but the Los Angeles Times reported it was for three years. His previous contract was set to expire at the end of the 2014 season.
The Dodgers made the playoffs for the first time in three years under Mattingly, 52, who has a 260-225 career managerial record with Los Angeles.