Jennings was mainly a self-taught artist born in Old Hill, Staffordshire. He worked in oil and watercolour and was a self-employed painter from 1960. He was noted as a painter of the English countryside. He lived in Kidderminster, Worcestershire.
Jennings showed with RcamA, NEAC, ROI, RBSA, The Game Fair and elsewhere in mixed exhibitions. He had a series of solo exhibitions in London and the provinces, also exhibiting in America and on the continent.
Royle, Medici, Solomon and Whitehead and other publishers reproduced his work. Valentine’s of Dundee published a painting chosen by HM Queen Elizabeth the Queen Mother as her personal Christmas card.
Jennings also helped restore early stained glass windows, including some in the House of Commons; he made a video on oil painting for Optical Image Ltd; and painted a mural for Fortox of Kidderminster depicting 300 years of family history.