The deal also includes up to $750,000 in incentives. The Twins cleared room on their 40-man roster after Steve Tolleson was claimed off waivers from the Athletics on Monday.
The Twins had been looking for ways to upgrade a relatively thin bench, and they're hoping Thome -- with his 564 home runs over a 19-year career -- can help. Although the five-time All-Star has been an everyday player throughout his career, he primarily served as a lefty power hitter off the bench with the Dodgers toward the end of 2009, batting .235 (4-for-17) with three RBIs.
Thome, who made $13 million in 2009, recently said the White Sox and Rays were also interested. In the end, however, it was the Twins' aggressive pursuit coupled with his familiarity with the American League Central that led him to sign with Minnesota.
"They were really excited about me coming there, and so to me, it was a no-brainer," said Thome. "I've always enjoyed the way they've played and how they've gone about their business. To be a part of that, it will be a lot of fun to go there and help them win."
Thome, currently five home runs shy of Rafael Palmeiro for 11th place on the all-time list, batted .249 with 23 homers and 74 RBIs in 107 games with the White Sox in 2009 before being dealt to Los Angeles on Aug. 31.
For his career, he sports a .277 batting average and is a .220 hitter with three homers over 99 plate appearances in the pinch-hit role.
The Twins already have a lefty-hitting designated hitter in Jason Kubel, and the club is committed to Delmon Young as its everyday left fielder. So Thome -- primarily a DH the past four years -- will be relegated to a bench role.
And Twins manager Ron Gardenhire couldn't be happier.
"We just signed a guy that's going to be in the Hall of Fame and it doesn't get much better than that," Gardenhire said during a conference call to announce the deal on Tuesday night. "One of the classiest acts in the game. A great hitter, a great player and great for our clubhouse. I think we got the package deal here."
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.