George K. Gillespie was born in Belfast in 1924. He was educated at Belfast High School before attending evening classes from 1945 at the Belfast College of Art, Gillespie studied jewellery and silversmithing alongside painting. Attending classes at the studio of R. Boyd Morrison encouraged Gillespie’s pursuit in painting, as he adopted it professionally from 1977. Focusing on the Irish landscape, he often depicted scenes of Donegal, and also Connemara and the West Coast.
Gillespie exhibited at the Oriel Gallery, Dublin in 1980 and later at the Kenny Gallery, Galway. His work is included in the collections of the Department of the Environment for Northern Ireland and the Office of Public Works in Dublin, along with numerous private collections.