A method and system for supplemental sleep detection is described. A system may receive data associated with a user from a wearable device worn by the user, and may detect a primary sleep period for the user based on the received data. The system may additionally detect a supplemental sleep period including a duration that exceeds a threshold duration based on the received data. In some implementations, the system may cause a graphical user interface (GUI) of a user device to display an indication of the detected supplemental sleep period, and may receive a confirmation of the supplemental sleep period via the user device and in response to the indication of the detected supplemental sleep period. The system may subsequently generate one or more insights associated with the user based on the primary sleep period and the supplemental sleep period and, in some implementations, in response to the confirmation.