Per MLB Network's Jon Morosi, the contract will be for one year and is worth $12 million guaranteed.
Lynn was one of the last major dominoes to fall in a slow-moving free-agent market, along with fellow starting pitchers Jake Arrieta and Alex Cobb.
After missing all of 2016 while undergoing Tommy John surgery, Lynn completed a full season while making 33 starts and tallying 186.1 innings in 2017. He finished the year with an 11-8 record and a 3.43 ERA, while his 1.229 WHIP was the lowest of any full season of his career.
His solid performance in his first year back from injury is a great sign for his future, especially after proving to be one of the most consistent starters in the majors over his time with the St. Louis Cardinals.
In five full seasons, Lynn has won at least 10 games each year and has never posted an ERA higher than 4.00.
If he had 23 more innings pitched, he would rank 12th among active pitchers with a 3.38 career ERA, ahead of established players like Zack Greinke and Justin Verlander.
Although the 30-year-old saw his walks rise and his strikeouts decline over the past year, he remains a front-of-the-rotation starter who represents a major upgrade with his new team.
He already has an All-Star appearance and a World Series ring on his resume, but Lynn still has a lot to accomplish as his career progresses.
Lynn figures to be part of a new-look Twins rotation that also added Jake Odorizzi from the Tampa Bay Rays this offseason.
He will likely slide in as a No. 3 or No. 4 starter with Jose Berrios and Ervin Santana (after he returns from injury) residing near the top of the rotation.