Marie-Josée Lord made her professional debut in 2003, singing Liù in Puccini's Turandot at the Opéra de Québec. In 2004, Montreal music lovers were enraptured by her rendition of Mimi in Puccini's La Bohème at the Opéra de Montréal where, in 2005, she also sang Laoula in Chabrier's L'étoile.

In 2006, she could be heard in the title role in in the Opéra de Montréal's season-opening production of Suor Angelica (Puccini). She has also been heard as Marie-Jeanne in the world premiere of the operatic version of Starmania (Plamondon/ Berger) at the Opéra de Québec in 2008 and at the Opéra de Montréal in 2009. She brilliantly sang the role of Nedda (I Paggliacci) at the Opéra de Montréal in 2009, and that of Meg Page in Falsta (Verdi) at the Opéra de Québec in 2012.

In 2014, she sang the role of Serena when, for the first time, the Opéra de Montréal mounted performances of Gershwin's Porgy and Bess. More recently, in 2017, the Montreal public was able to hear her again, singing the role of Mme. Lidoine in the first-ever production of Poulenc's dialogues des Carmélites in this city.

With her irresistible charisma, generosity, and passion for the lyric art, Marie-Josée Lord is a favourite guest on several television and radio shows (Tout le monde en parle, Studio 12, En direct de l'univers, etc.). On October 28, 2012, Marie-Josée made her Toronto debut at the Royal Conservatory of Music's prestigious Koerner Hall as part of the Montréal-Toronto series.

Marie-Josée Lord has performed several times with the Montreal Symphony Orchestra, the Orchestre Symphonique de Québec, and the Orchestre Métropolitain, under the direction of a number of conductors, including Kent Nagano, Yannick Nézet-Séguin, Paul Nadler, Alain Trudel, and many others.