Barton studied at the College of Fine Arts of the University of New South Wales, graduating with a Bachelor of Fine Arts in 1993. She was later employed at the College as a lecturer.[4] She has held numerous solo exhibitions in Sydney and Melbourne since her first in 1995.[5]

Her solo exhibitions include: The Nightingale and the Rose, Australian Centre for the Moving Image (ACMI), Melbourne, Australia (2016); the highway is a disco, ARNDT, Singapore (2015); Electro Orchid, Roslyn Oxley9 Gallery, Sydney (2014); The Nightingale and the Rose, Heide Museum of Modern Art (2012); the stars eat your body, Kaliman Gallery, Sydney (2009); the whole of everything, Karen Woodbury Gallery, Melbourne (2008) and thank you for loving me, Karen Woodbury Gallery, Melbourne (2005).[6]

On 7 March 2008, it was announced that Barton had won the 2008 Archibald Prize for portraiture, for You are what is most beautiful about me, a self portrait with Kell and Arella, a self-portrait with her two children. Barton said of the portrait: "This painting celebrates the love I have for my two children and how my relationship with them has radically informed and indeed transformed my understanding of who I am". In 2013, she won the Archibald Prize for her portrait of actor Hugo Weaving. Of portraiture generally, she says: "I really value the discipline" that it brings.

She was also an Archibald Prize finalist in 2008, 2013 and 2018.