Raised in Porto-Vecchio, South of Corsica, where she started theater at age 14, Eva O'Neill then moved to Paris, France in 2017 to pursue acting as a career. She enrolled in the Cours Florent for a year and then graduated from the Cours Eva St Paul in 2021, before attending acting and screenwriting courses at the Royal Conservatoire of Scotland. Later she joined Playhouse Paris where she trained in Meisner technique with Tracy and Mark Pellegrino and sharpened her acting skills. She also deepened her screenwriting education in Paris. She is trained in stage acting, acting for camera, stage combat, light stunts, martial arts, improvisation and singing for musicals.