Pierre Bastien (born 1953 in Paris) is a French musician, composer, and experimental musical instrument builder.

Bastien began building mechanical-based musical instruments at an early age, using items such as metronomes, cymbals, and pulleys.

In 1986, he formed his own orchestra, Mecanium, composed of Meccano machines which play various instruments, such as Chinese lute, Moroccan bendir, Javanese saron, koto, and violin.

By the 1990s, Mecanium consisted of up to 80 machine 'musicians', and toured various art and music festivals, including events in Norway, Australia, Japan, Canada, Poland, and the United States.

Bastien has collaborated with artists such as Robert Wyatt, Jac Berrocal, Emmanuelle Parrenin, Jaki Liebezeit, Pierrick Sorin, Lukas Simonis and Issey Miyake.