Born in Massachusetts in 1717, John Grillo began his studies in art at the Hartford Art School (1935-1938). In 1947, he went to the west coast where he studied for two years at the California School of Fine Arts. He later studied under Hans Hoffman in New York and the Hans Hoffman School of Fine Arts, Provincetown, Massachusetts (1948-1951). Grillo remained active in Provincetown, Massachusetts during much of his career.

In 1964, he returned to Los Angeles, California to work at the Tamarind Lithography Workshop under a Ford Foundation grant. That same year, he received the Ford Foundation artist-in-residence grant at Butler Institute of American Art in Youngstown, Ohio. John Grillo taught at the New School for Social Research, in New York (1964-1966) and the University of Massachusetts at Amherst (1967-1991). Grillo exhibited widely in California, New York and Massachusetts and is known for his Abstract Expressionist paintings.