Robert Hamilton (1917-2004) was born in Seneca Falls, New York, and attended the Rhode Island School of Design from 1935 to 1939. In 1940, he studied at the Art Students League in NYC. During WWII, he served as a P-47 fighter pilot, flying 100 missions and earning the Distinguished Flying Cross. At the end of his service, he was recruited by RISD to teach drawing and painting at the college, a position he held for 34 years, from 1948 to 1981, when he retired to Port Clyde, Maine. 

During the 1950s and 1960s, he showed his work widely at galleries and museums throughout the Northeast, including annual shows at Kanegis Gallery and Alpha Gallery in Boston, as well as at Cornell University, the ICA Boston, the Carnegie Museum of Art, and the DeCordova Museum, among others.

In 1974, Hamilton was Artist in Residence at the American Academy in Rome. During the later decades of his career, he chose to exhibit his work primarily at The Octagon, an eight-sided gallery he built on his property in Port Clyde. In 1999, he had solo exhibitions at the Farnsworth Art Museum and the RISD Museum, and in 2011, at the Center for Maine Contemporary Art. His work is in the permanent collections of the Farnsworth Art Museum, Portland Museum of Art, Brown University, MIT List Art Center, Rose Art Museum, DeCordova Museum, Tougaloo College, University of Tennessee, and the RISD Museum. 

Hamilton's lifelong love of jazz—his son is the noted jazz saxophonist Scott Hamilton—is reflected in the syncopation of his colors and idiosyncratic compositions. "I knew my paintings had to be improvised, spontaneous, made up out of whole cloth, one thing leading to another, accidental, a series of metamorphoses, surprised arrivals," he wrote. His close friend and neighbor, Andrew Wyeth, called Hamilton "a real painter."