The Wild announced the deal on Friday. The 25-year-old Kassian played in 24 games for the Wild last season. He scored both of his goals in a game against Montreal on March 1 and racked up 55 penalty minutes.
The 6-foot-4 Kassian was picked in the second round of the 2005 draft and debuted with the Wild in 2010.
The Wild also signed defenseman Chay Genoway to a two-year deal. He had seven goals and 29 assists for the Houston Aeros of the AHL last season and made his NHL debut in the season finale last year.