Mauk played for Melbourne City last season on loan from the Nijmegen-based team, making 23 appearances and scoring five goals as City made the semi-finals. 
Last season N.E.C were relegated from the Eredivisie and will take part in the Dutch second division, the Eerste Divisie, this season.
Alongside forging a sterling reputation in the A-League, the 22-year-old midfielder has been a regular for Australian youth national sides, making 15 appearances for the Olyroos since 2014. He is yet to appear for the Socceroos.
“I believe the Brisbane Roar is a perfect place for me to develop and I’m delighted to commit my long-term future to the club. I’m looking forward to a successful future,” Mauk said.
“I’m excited to team up with the Roar and John Aloisi who I’ve worked with previously. He gave me my first opportunity as a professional footballer and I’m keen to improve my game in Brisbane.
“We’ve made some really good signings and the squad is shaping up nicely. Scoring goals is a massive part of my game and I’m here to do that and help us win another title.
“Finally, I’d like to thank my agent and all parties involved for making this move possible. I can’t wait for season 2018/19 to begin.”
Aloisi believes the recruitment of Mauk, alongside other new attacking talent Adam Taggart and Dylan Wenzel-Halls, means Brisbane's recruitment is nearly complete.
"We're extremely pleased to secure a talented young Australian footballer who has committed his long-term future to BRFC," Aloisi said.
"I remember giving Stefan his Hyundai A-League debut approximately five years ago and ever since I’ve been following his progress closely.
"We are very confident that he will suit our style of play and excite our supporters and the local football community.
"Our squad is nearly complete and I know the players are hungry for success. We are working hard as a group to be successful in 2018/19 and beyond."