Ronald Grenville Millar was born in Donald, Victoria. He began exhibiting in 1956 and since has had over 20 solo exhibitions. He was a lecturer in painting at RMIT for 18 years and art critic for the Australian and Melbourne Herald. He has won numerous awards for painting including the Fairley Prize, the Gold Coast Prize, the Rockhampton Prize (twice), and the Swan Hill Prize.
Ronald Millar is represented in many collections including the Art Gallery of WA, Art Gallery of Qld, Mornington Peninsula Art Gallery, Shepperton Regional Gallery, Horsham Regional Gallery and Swan Hill Regional Gallery of Contemporary Art.