Wallis was born in Devon. He was a fisherman and later a scrap-metal merchant in St. Ives. After the death of his wife in 1922, he turned to painting. He was admired by Ben Nicholson and Christopher Wood, who came across his work when visiting St Ives in 1928 and included it in the Seven & Five Society's exhibition of 1929. He died in Madron Poorhouse.