Vanessa O'Neill trained as an actor at the Ecole Philippe Gaulier and at the Drama Centre in London and since then she has worked for a range of theatre companies including The Australian Shakespeare Company, La Mama, Shakespeare by The Sea, Harlos Theatre Company, Sydney Art Theatre, Bell Shakespeare, and The Arts
Centre, Victoria.
From 2001 – 2004 O'Neill toured her one-woman-show Happy With Half Your Life across Australia, the United Kingdom and Europe, with the assistance of The Australia Council for the Arts. She has has also toured schools throughout Australia with a solo show of Shakespeare’s Women, and in 2013 took part in the International Fellowship at Shakespeare’s Globe. She has also been employed as the Youth and Education Manager at Melbourne's Malthouse Theatre.
In 2016 Currency Press, in association with La Mama Theatre, published her play In Search of Owen Roe.