Fifth Business (1970) is a novel by Canadian writer Robertson Davies, who is also a playwright, critic, journalist, and professor. It is the first installment of the Deptford Trilogy and explores the life of the narrator, Dunstan Ramsay. It is Davies' best-known novel and has been ranked as his finest. First published by Macmillan of Canada in 1970, Fifth Business was ranked as 40th on the American Modern Library's "reader's list" of the 100 best novels of the 20th century.