Nadeau was born on September 30, 1997, in Montreal, Quebec. He has three older sisters – Tania, Pamela, and Mélissa. He enjoys skiing in addition to figure skating.
Career
Early years
Nadeau began learning to skate in 2003. He is coached by Yvan Desjardins since 2011 or earlier. Competing on the junior level, Nadeau placed sixth at the 2013 Canadian Championships and fourth in 2014.
In 2015–2016, Nadeau started his season at the JGP in Riga, Latvia; he finished fifth after placing second in the short program and seventh in the free skate. He won the silver medal at his second JGP event, in Zagreb, Croatia, finishing 0.38 points behind the gold medalist, Alexander Samarin. In January 2016, Nadeau placed fifth on the senior level at the 2016 Canadian Nationals and was given Canada's sole spot in men's singles at the 2016 World Junior Championships in Debrecen, Hungary. Competing in March at Junior Worlds, he qualified for the final segment by placing eighth in the short program and second in the free skate, winning the silver medal overall.
2016–2017 season
Nadeau withdrew from his JGP assignments due to an ankle injury, which occurred while practicing a quad toe loop jump and took about three months to heal. He returned to competition at the 2016 CS Golden Spin of Zagreb, his first senior international, and finished 11th. At the 2017 Canadian Championships, he placed fifth in the short program, third in the free skate, and fourth overall.
Beginning the season at the 2018 Finlandia Trophy, Nadeau placed fourth, less than four points behind from bronze medalist Morisi Kvitelashvili. Nadeau said that he needed to work on executing the one quadruple jump in his free skate. He subsequently competed in the short program at his lone Grand Prix assignment for the year, the 2018 Internationaux de France, but withdrew for medical reasons. At the 2019 Canadian Championships, Nadeau placed seventh in the short program after singling his triple Axel attempt and receiving a negative Grade of Execution on his quadruple toe loop. He rallied in the free skate, where he placed fourth, and moved up to sixth place overall. Nadeau called it "an even better program than what I expected, but it had to compensate for the short." While he finished sixth overall, three of the skaters who finished ahead of him were ineligible to compete as seniors due to either their age or a lack of the required minimum technical scores, and consequently Nadeau was named to Canada's team for the 2019 Four Continents Championships, when he finished eleventh.
2019–2020 season
After withdrawing from the 2019 CS U.S. Classic, Nadeau competed on the Grand Prix at the 2019 Skate Canada International. Eighth in the short program with a clean skate but for a problematic landing on his triple loop, he rose to seventh overall after a sixth-place free skate. He was seventh as well at the 2019 Internationaux de France. Nadeau placed fifth at the 2020 Canadian Championships.
Skating technique
Unlike most skaters, Nadeau jumps and spins clockwise.
