Norman Thelwell was born in Birkenhead, Cheshire, on 3 May 1923. His earliest surviving drawing is a pencil self-portrait done at the age of 10, on which his teacher has written in red ink: ‘V. good indeed’. He remembers always wanting to draw as a child and recalls finding drawing and painting much easier than other subjects – ‘with drawing, the answer was always there in front of you – you only had to look’. His love of the countryside was fostered by childhood visits to a North Wales farm and was strengthened throughout his life.
He joined the Army in 1941 and, through the years of war which followed, both in Britain and in India, he always travelled with his sketchbooks. The first cartoon he ever had reproduced was an Indian subject for the London Opinion. In 1945, at Nottingham Art School evening classes, he met fellow student Rhona whom he married in 1949. After the war, he took a degree course at Liverpool College of Art and in 1950 he started teaching design and illustration at Wolverhampton College of Art.