He started the season at the JGP in France where he finished ninth. He did better at his second JGP event, in Turkey, earning the bronze medal. At the Canadian Championships, he placed sixth in the senior division. He finished the season at the World Junior Championships in Milan, Italy, where he placed twelfth. The next season, he placed fourth and 16th at his two JGP events. Competing at the senior level, he placed fifth at the Canadian Championships. He then competed at his first senior international, the Four Continents Championships, and placed tenth. Afterwards, at the World Junior Championships in Sofia, Bulgaria, he placed first in both segments and won the gold medal. He finished the season at the senior World Championships, where he placed twelfth. Nguyen started the season with a silver medal at the inaugural Skate Canada Autumn Classic, an ISU Challenger Series event. He made his senior Grand Prix debut at the Skate America, winning the bronze medal. He continued to his second Grand Prix event, the Cup of China, where he placed fourth. This placed him ninth in the final Grand Prix standings, making him third alternate for the final. In December, he won the gold medal at the Skate Canada Challenge, the qualifying event for Canadian Nationals. In January, he won his first senior national title, outscoring the silver medallist by more than 30 points. After placing eleventh at the 2015 Four Continents, he finished fifth at the 2015 World Championships in Shanghai, recording his personal best scores in both segments. Nguyen started his season by winning silver at the 2015 Skate Canada Autumn Classic. Turning to the Grand Prix series, he placed fifth at the 2015 Skate Canada International and seventh at 2015 Rostelecom Cup. Nguyen finished fourth at the 2016 Canadian Nationals. He was assigned to the 2016 World Championships in Boston after Liam Firus withdrew. He failed to qualify to the free skating. In an interview at the 2016 Team Challenge Cup, he mentioned his planned coaching change to David Glynn. Skate Canada confirmed the change a few days later, stating that Nguyen would move to San Jose in May. Nguyen placed fifth at the 2016 CS U.S. International Classic. On the Grand Prix series, he placed sixth at the 2016 Skate America and eighth at the 2016 NHK Trophy. After returning to Ontario in December 2016, he began training at the York Region Skating Academy, coached by Tracey Wainman and Grzegorz Filipowski.