The 29-year-old joined Wildcats from Catalans Dragons on a two-year deal ahead of the 2015 season.
He has signed on for an extra 12 months, with the option of a further year.
Simon, who has nine Test caps and made nine appearances for Wildcats this season, said: “I am very happy to stay here, especially as I have built up a great relationship with the rest of the squad and the coaching staff.
“It is a good opportunity for me. The club has grown over the past year and it is nice to know I am part of Chris Chester’s plans for the future.”
Coach Chester said: “I am pleased we have been able to secure Mika for another year, he is a fantastic player.
“He’s been a stand out performer for us this season and I am looking forward to see what else he has to show us over the next year.
“The main intention for the club is to keep all of our best players and I feel we are on the right path to do this.”