McDonnell studied at the Art Academy in Munich and later moved to Vienna where he spent a year working in a studio of the sculptor and architect Fritz Wotruba. Following the continental experience, about 1967 McDonnell entered Christ Church, Oxford College to study history. On graduating from Oxford, he began to exhibit his paintings regularly in London.

Self-confessedly, Hector McDonnell is a loner, a maverick, an unbranded steer. As a completely figurative painter in the early 1970s he was out on a limb. The fashionable contemporary art at that time was abstract, pop or conceptual. His output is prolific. He produces a large quantity of oil paintings, both very large and very small, using dashing thick square brushstrokes, and presumably painted very quickly. His speciality is interiors, usually with a lot of floor in the foreground. These are often pub and cafe interiors, but more particularly shops, especially butchers, fishmongers and greengrocers. He also regularly produces small sets of etchings on the same subject.

McDonnell allows himself to be seduced by what he sees: events startle him into perceiving what he calls the ‘magical’ in everyday situations. In his painting each object is imagined with the stout atmospheric density he needs to give form to his feelings. It might almost be possible to describe this as ‘folkloristic’, if by that one meant the creative fluency with language that turns the simplest Irishman into a poet – where the word is an integral part of man’s being poetry and naturalism lie side by side.

McDonnell now spends much of the year in New York City,