In mathematics, Denjoy's theorem may refer to several theorems proved by Arnaud Denjoy, including

Denjoy–Carleman theorem Denjoy–Koksma inequality Denjoy–Luzin theorem Denjoy–Luzin–Saks theorem Denjoy–Riesz theorem Denjoy–Wolff theorem Denjoy–Young–Saks theorem Denjoy's theorem on rotation number