An optical sensor module includes a support unit, a light-receiving unit and a light-emitting unit. The support unit includes a main plate, and a side plate inclined relative to the main plate. The light-receiving unit includes a photodetector disposed on the main plate and having a light-receiving surface located away from the main plate, and a light-blocking member covering part of the photodetector. The light-emitting unit emits light toward an imaginary line perpendicular to the light-receiving surface, and is disposed on the side plate. A wearable device including the optical sensor is also disclosed.