General manager Scott Howson announced the deal on Tuesday.
The 26-year-old Methot has become one of the Blue Jackets' most reliable blue-liners. He has six goals and 38 assists in 229 career NHL games with Columbus. Last season, he had 15 assists and 58 penalty minutes and was plus-2 in 74 games, setting career highs in assists, penalty minutes, games played and ice time.
He ranked second on the club with 176 hits and was third with 98 blocked shots.
Columbus' seventh pick, and No. 168 overall, in the 2003 draft, Methot made his NHL debut in 2006-07.