Financial terms of the deal were not disclosed but La Russa was expected to receive a deal in excess of $2 million per season.
La Russa was unsure in October whether he would be back and speculation increased when Mark McGwire, his longtime friend, announced his retirement in November. But St. Louis has been one of the more active teams this offseason and La Russa agreed to a new three-year pact.
"We're happy to have a deal officially in place now," Cardinals general manager Walt Jocketty said. "Tony is regarded as one of the game's best managers and we feel that he and his staff will continue to give us our best chance at securing a 10th world championship for the Cardinals and their fans."
The 57-year-old La Russa is 507-464 in six years at the helm of the Cardinals and he and Leo Durocher are the only managers ever to win 500 games with three different teams. His 1,827 career wins is 11th all-time and the most among active managers.
After breaking in as the manager of the Chicago White Sox in 1979, La Russa joined the Oakland Athletics in the middle of the 1986 season. He guided the A's to a World Series championship in 1989, the middle year of the three straight appearances in the Fall Classic.
La Russa has guided the Cardinals to the postseason each of the last two seasons and three times in his six years. But St. Louis is just 2-3 in playoff series under La Russa.
La Russa's 23 straight years as a major league manager are surpassed only by Connie Mack of the Philadelphia Athletics (1901-1950), John McGraw (1901-1931) and Sparky Anderson (1970-95).