Cullen has agreed to a one-year, $1 million contract with $700,000 in potential bonuses.
Cullen, 40, had 13 points and 18 assists during the regular season and added two goals and seven assists during the Penguins' playoff run last season.
This will mark Cullen's second stint with the Wild. He played three seasons for Minnesota from 2010 to '13, scoring 33 goals. He also went to high school in Minnesota and played two seasons for St. Cloud State.
Cullen has 248 goals and 441 assists in 19 seasons for the Mighty Ducks, Hurricanes, Wild, Panthers, Predators, Rangers, Senators and Penguins, winning his first Cup in 2006 with Carolina.
The Wild were second in the Central Division last season with 106 points but lost to the Blues in the first round of the playoffs. This offseason they re-signed Nino Niederreiter and Mikael Granlund and traded Marco Scandella and Jason Pominville to the Sabres for Tyler Ennis and Marcus Foligno.