On February 25, 2018, Maroon was traded to the New Jersey Devils in exchange for J. D. Dudek and a third-round pick in the 2019 NHL Entry Draft. He was displeased with the trade and said "I didn’t really want to get traded out of Edmonton...I actually loved it there. I actually liked it. The fans are great. I liked it. You know what the most important thing was? The guys were great. Unbelievable guys. You could not have found a better group of guys. But obviously I got traded for a reason. We weren’t winning." He made an immediate impact on the team, recording eight points in his first 12 games and earned praise from his teammates on his playmaking ability. Center Travis Zajac spoke highly of Maroon saying, "we're a high-skill, fast team, but you add a player like Patty who can grind away and protect the puck, and bring pucks to the net, go to the net, it adds another threat for us, and it's been a good addition." He ended the season with 13 points in 16 games as he underwent surgery during the offseason to repair a herniated disc in his back.