Héloïse Gaillard is best known as the director of the early music group Ensemble Amarillis but also performs as a solo flutist and recorder player. Gaillard has been a member of several leading French early music ensembles. In 1994, Gaillard, her sister Baroque cellist Ophélie, and harpsichordist Violaine Cochard founded Ensemble Amarillis in Paris. As of the early 2020s, Gaillard remains the group's artistic director. She has also performed and recorded as a soloist, releasing an album of Telemann's Fantasies for solo flute in 2013, and has performed as a member of top French early music groups. In 2022, Gaillard and Ensemble Amarillis released an album of solo cantatas and instrumental works by Élisabeth Jacquet de la Guerre.