An Australian-American, O’Neill, was born in Wangaratta, Australia, and currently lives and works between Australia and Brooklyn, New York.

O'Neill attended Monash University, Melbourne, Australia, earning a BFA and Post Graduate Degree. Her post-graduate work continued at the New York Studio School's Certificate Program, and her MFA was completed at Brooklyn College in 2012. In 2007 she received a Joan Mitchell Foundation award. O’Neill’s solo exhibitions include at David Schweitzer Contemporary, Bushwick, NY; Hathaway Contemporary, Atlanta, GA and Miller Gallery, Cincinnati, OH; BMG Gallery, Adelaide, Australia; TW Fine Art, Brisbane, Australia; Life on Mars Gallery, Brooklyn, NY, John Davis Gallery, NY; New York Studio School, NY; and Sussex College, Hastings, UK. In 2016 her work was exhibited at MOCA in Jacksonville, FL in a group exhibition titled Confronting the Canvas: Women of Abstraction.

O’Neill’s work has been included in various group shows through out the USA and in Australia. She has recently taught at the New York Studio School, Arts Students League and Pratt Institute.

Her work resides in private collections in the USA, Australia and UK, and in the permanent collection of MOCA Jacksonville, FL.