The publisher of the earliest HP Lovecraft horror stories, he also had a career as a multi-genre author. His works include the Sac Prairie Saga; novels such as Murder Stalks the Wakely Family (1934) and Bright Journey (1940); and numerous short stories, essays, and poems.
A prolific reader in his youth, he sometimes made three trips a week to the local library. He published his first work of short fiction, Bat's Belfry, in 1926.
Though best known for his horror stories, he also wrote extensively about the people and places of his native Wisconsin.
He was born in Sauk City, Wisconsin to Rose Louise Volk and William Julius Derleth. He graduated from the University of Wisconsin in 1930.
He was a close friend of H.P. Lovecraft; his publishing company, Arkham House, published many of Lovecraft's early works.