Guy Denning's paintings have been shown in numerous solo and mixed exhibitions. Notable solo shows include 'Behemoth' at St Martin in the Fields, London, 'Celebrity will Eat Itself' at Carmichael Gallery, Los Angeles, and the '5/11' Show at Red Propeller, Kingsbridge. His work is held in several important public collections, including the Politics Department of Bristol University, the Political Science Department at Galway University and the UK Pituitary Foundation.    

Denning's early work included an interest in the work of Franz Kline and was characterised by powerful, expressive brushstrokes in mainly abstract paintings. More recently he has combined earlier influences with an increasingly figurative style of painting. The human figure features strongly in his latest work and he uses this subject matter to convey powerful emotions, often with political overtones. The Icarus series of works is an example of this approach. Structurally his work is very dynamic showing a concern for strong draughtsmanship with a spontaneous application of colour He does not work to set motifs, but makes paintings and drawings from observation and photographic reference.  

Guy Denning uses not only powerful brush strokes to express his emotions deeply but also scratches the paint to show the audience the intensity of the emotions he is trying to portray with his artwork. Guy Denning's Requiem 2 is a good example of this. Denning's work involves other techniques such as blacking out eyes and mouths maybe to emphasize Denning's theme of darkness, horror and maybe even despair. He also sometimes uses stencils and collaged text. A question that is often asked about Denning's work is whether it reflects his own emotions and feelings or is the artwork simply presented the way it is to emphasize the condition of the subject.