Maddox was born in Herefordshire. He produces paintings, objects and collages in a surrealist style. He refused to enter any of his work in the International Surrealist Exhibition in London in 1936, arguing that most of the artists chosen were 'anti-surrealist'. The following year he was introduced to the Paris surrealist group by Georges Hugnet. Maddox joined the short-lived English surrealist group in 1938. Much of his work is inspired by his antagonism towards religion. He has worked consistently in a surrealist style since the 1930s.