Frank Middleditch was born in Edmonton, Middlesex. He was educated at Stationers' Company's School in Hornsey, after which he won a scholarship to Hornsey College of Art. He trained as an industrial designer and was a member of the Society of Industrial Artists (MSIA).

Prior to World War II he spent some years working in India, including volunteering in the Calcutta Light Horse Regiment. On returning to the UK, a radio he designed for Bush was in the 1946 'Britain Can Make It' exhibition at the V&A. The model, originally in black, became immensely popular and was then produced in several colours, as well as for the export market with translated words; a mahogany-coloured version is in the permanent collection of the V&A.

In 1935 he married a classically trained singer, Felise. During the 1950s they were living in Lympstone near Exmouth in Devon. Alongside Clifford FISHWICK and Amy ELTON, he became a member of the Kenn Group, a society of professional artists based in Exeter, whose group shows were usually held in the city's Royal Albert Memorial Museum (RAMM).

In 1962 he and Felise moved to Cornwall and were living at Fenton Pits, outside Bodmin, and later they moved to Egloshayle, Wadebridge. In 1963 Frank had a solo show of paintings at the Poly, Falmouth, and a solo show of engraved slate, collages and drawings in the RAMM in 1971. During a long artistic career, his work was also shown at the New English Art Club, Royal Academy, Royal West of England Academy, Birmingham City Gallery and Brighton City Gallery.

He died in Truro in 1996.