He studied at the Royal Conservatory of Liège in Belgium and later with Luigi Alva, Alain Vanzo, and Gabriel Bacquier.

He made his professional opera debut at the Opéra de Monte-Carlo in 1989 as l'officier in Massenet's Thérèse.

In September 2012 he could be heard singing the title role in Stradella by César Franck, a world premiere for the reopening of the Royal Opera of Wallonia in Liège.

Marc Laho appeared as Fernand in Donizetti's La favorite at the Théâtre des Champs-Élysées in February 2013.

In 2018 he appeared as Don José in a video-recorded performance of Bizet's Carmen by the Opéra Royal de Liège.