Trevor Bell was born in Leeds and studied at Leeds College of Art from 1947 - 1952. After a period as a teacher at Harrogate College of Art, and on the advice of the artist Terry Frost, in 1955 Bell and his wife, Dee moved to St Ives and started to make his reputation as a leading member of the middle generation of St Ives artists, along with his peers Patrick Heron, Anthony Benjamin, Bryan Wynter and Terry Frost. When Anthony Benjamin returned from Paris to St. Ives in 1959 he shared a studio with Trevor Bell on Porthmeor Beach, next to the visiting Francis Bacon who had borrowed Redgrave’s studio though the winter of 1959-60.

Bell exhibited with the Penwith Society of Arts from 1956 and had his first solo exhibition at Waddington Galleries in 1958. In the catalogue notes of Trevor Bell's first exhibition at the Waddington Galleries in 1958, Patrick Heron famously wrote, "To me he appears as the best non-figurative painter under thirty in this country."

In 1959, Bell won the 'Paris Biennale International Painting' award and after short periods in Italy, Bell took up a Gregory Fellowship at Leeds University in 1960. In Leeds, Bell continued a mode of painting inspired by landscape, nature and the elemental forces of weather that he had developed in Cornwall.

After his exhibition at the Whitechapel Art Gallery in London in 1973, Bell went onto became Professor for Master (Graduate) Painting at the Florida State University, staying there for over 20 years before returning to Cornwall in the 1990s from the United States.