General manager Don Maloney announced the long-term deal Friday, but didn't disclose financial details.
The Coyotes are in Columbus to play the Blue Jackets on Saturday.
The 21-year-old Ekman-Larsson has three goals and 14 assists in 27 games this season and leads the Coyotes in ice time at 25:07 per game.
Last season, Ekman-Larsson career highs with 13 goals and 19 assists. He was one of six Phoenix players to play in all 82 regular-season games and ranked second on the team with 92 blocked shots.
The Swede was a first-round pick of the Coyotes in the 2009 draft at No. 6 overall.