The 30-year-old Hanzal signed a $14.3 million, three-year contract. The center had a career-high 20 goals while splitting last season between Arizona and Minnesota. He finished with 39 points (19 assists) in 71 games.
Dallas also added younger forward Tyler Pitlick on a $3 million, three-year contract on the first day of free agency. The 25-year-old spent parts of three seasons with Edmonton.
He was a trade-deadline pickup by the Wild from the Coyotes, the only team he had played for after the club drafted him 17th overall in 2005. Hanzal couldn't help Minnesota get out of the first round of the playoffs, scoring one goal in his first postseason action in five years during a five-game loss to the Blues.
Durability has been a concern with the 6-foot-6 center. Hanzal, 30, played in 71 games last season, the first time he had more than 70 appearances since 2009-10.
The 25-year-old Nemeth had three assists in a career-high 40 games with the Stars last season. He signed a one-year deal for $945,000 and is going into his fifth season.
Dallas also signed Brian Flynn to a one-year deal. He played for Montreal last season.
The Associated Press contributed to this report.