Abstract: A lock status indicator device (10) includes a base (12) secured to an outer surface (26) of a door (24) with a door lock (30). The door lock (30) includes a bolt (32) moveable between an extended, latching position and a retracted, unlatching position. A slider (14) is slideably mounted to the base (12) and includes first and second indicators (59, 65) on an outer face (56) of the slider (14) for indicating the door (24) is in a locked status not allowing the bolt (32) to be retracted from the latching position to the unlatching position or in an unlocked status allowing the bolt (32) to be retracted from the latching position to the unlatching position. A cam (16) is pivotably mounted to the base (12) and includes a guiding slot (61) through which a protrusion (58) of the slider (14) slideably extends. A shaft (18) is engaged with the cam (16) and operably connected to a turnknob (33) of the door lock (30).