Nadja (1928) is the second book published by the French surrealist André Breton. It begins with the question "Who am I?"
It is based on Breton's actual interactions with a young woman, Nadja (actually Léona Camille Ghislaine Delacourt 1902–1941), over the course of ten days, and is presumed to be a semi-autobiographical description of his relationship with a patient of Pierre Janet. The book's non-linear structure is grounded in reality by references to other Paris surrealists such as Louis Aragon and 44 photographs.