A sleep mask assembly includes a sleep mask that is wearable on a user's face such that the sleep mask covers the user's eyes. The sleep mask has a face portion and a flap portion. The face portion rests against the user's face when the sleep mask is worn. The flap portion is positionable in a deployed position has the flap portion resting against the user's forehead to facilitate the user to comfortably rest their forehead against a support object when the user is sleeping in a sitting position. The flap portion is positionable in a stored position having the flap portion resting against the face portion. A pair of elastomeric straps is each coupled to the sleep mask thereby facilitating the pair of elastomeric straps to be worn around the user's head for retaining the sleep mask on the user's face.