The club announced the move on its official Twitter feed.
The Cardinals do not reveal financial terms for player contracts, but Fanhouse.com reported that the deal is worth $3.3 million. Theriot made $2.6 million in 2010 as a first-year arbitration-eligible player.
Despite a down year at the plate for the former Cub and Dodger, he was likely due for a raise in his second year of arbitration eligibility. General manager John Mozeliak said on Monday that the club felt little urgency to ink Theriot to a multi-year deal, but on Tuesday the Cards did at least gain cost certainty on Theriot for 2011.
Reliever Kyle McClellan and infielder Brendan Ryan are the Cardinals' only remaining arbitration-eligible players. The club is exploring trade options with Ryan, who has been replaced by Theriot as the starting shortstop.
Matthew Leach is a reporter for MLB.com. Read his blog, Obviously, You're Not a Golfer and follow him on Twitter at @MatthewHLeach. This story was not subject to the approval of Major League Baseball or its clubs.