Gustave Barnes (9 May 1877 – 14 March 1921) was an Australian artist and modeller.
Barnes was born in Islington, Middlesex, England, the eldest son of John William Barnes, a plasterer, and his wife Ann Eliza, née May. The family migrated to Adelaide when Gustave was a child; his father establishing Barnes & Neate, a builders, palsters and modelling business. On leaving school Gustave Barnes had some training in modelling, but was also a musician; at 21 years of age went to Europe to continue his study of the violin.
Barnes obtained employment at the Doulton pottery works as a designer, painter and modeller, and during his evenings studied at the Royal College of Art, South Kensington. In 1908 he exhibited a water-colour, 'Suffolk Marshes', at the Royal Academy of Arts. He also played violin in Sir Edward Elgar's second orchestra. His father died in 1912 and Barnes returned to Adelaide to carry on the business.
Barnes did a great deal of landscape painting, and was very interested in black and white work. In 1915 he was employed to classify and catalogue prints and drawings at the Art Gallery of South Australia and shortly afterwards was made curator of the gallery. He proved himself to be conscientious and able, and his early death on 14 March 1921 was much regretted.
Barnes had married Annie May while in England in 1909 and his wife survived him with two children. He is represented by three pictures in the Adelaide gallery. He took up painting at a relatively late age, and some of his work suggests that had he lived longer he might have reached a higher position in Australian art than is usually given him.