Marcel Van Minh Phuc Long Nguyen (born 8 September 1987) is a retired German artistic gymnast and three-time Olympian, having represented Germany at the 2008, 2012, and 2016 Olympic Games.

[6] Nguyen competed at the 2008 Olympic Games in Beijing where he helped Germany place fourth in the team final.

[13] Nguyen was selected to represent Germany at the 2012 Summer Olympics alongside Philipp Boy, Fabian Hambüchen, Andreas Toba, and Sebastian Krimmer.

Individually he won two silver medals, the first in the men's all-around behind Kōhei Uchimura[13] and later on parallel bars behind Feng Zhe.

[20] In October Nguyen competed at the 2017 World Championships in Montreal and placed seventh on the parallel bars with a score of 14.700.

[21] Following the World Championships he competed at the Arthur Gander Memorial where he won silver behind Oleg Verniaiev of Ukraine[22] and placed fifth at the Swiss Cup where he was partnered with Elisabeth Seitz.

[23] Nguyen finished his season at the Cottbus World Cup where he won bronze on parallel bars and placed fifth on still rings.

[25] In August he represented Germany at the European Championships where he qualified to the floor exercise and rings event finals.

[26] The following month Nguyen competed at the German National Championships where he placed first in the all-around ahead of Andreas Toba.

[29] He next competed at the Swiss Cup where he was partnered with Elisabeth Seitz; together they finished first ahead of the Russian duo of Angelina Melnikova and Nikita Nagornyy.

[30] Nguyen ended the season competing at the Cottbus World Cup where he finished fifth on both floor exercise and parallel bars.

[32] After he recovered he competed at the Stuttgart World Cup where he finished fourth behind Artur Dalaloyan, Sun Wei, and Petro Pakhniuk.

[36] In May 2021 Nguyen tore a cruciate ligament in his right knee which ended his bid to compete at the upcoming Olympic Games in Tokyo.