Courtois studied classical cello at the Conservatory of Aubervilliers, first with Erwan Fauré, and then with Roland Pidoux and Frédéric Lodéon.

In addition he started his own quartet in 1990, releasing his debut solo album Cello News the same year.

In 1995 Courtois performed his first solo concerts, he played within François Corneloup's Septett, and collaborated with Louis Sclavis making music for film and theatre.

He also recorded two albums with the quintet of Rabih Abou-Khalil, and in 1998 he participated in an ensemble led by Pierre Favre, and a trio with Yves Robert.

With Stefano Battaglia/Michele Rabbia/Dominique Pifarély/Michel Godard With John Greaves, Sophia Domancich With Michael Riessler & Singer Pur With Michele Rabbia and Marilyn Crispell With Daniel Erdmann, Samuel Rohrer and Frank Möbus With Joëlle Léandre With Louis Sclavis and Dominique Pifarely With Adam Bałdych With Fie Schouten clarinets and Guus Janssen keyboards With Rabih Abou-Khalil