A mounting apparatus for mounting a hard disk drive which does not require screws or tools includes bracket and latching unit. The bracket includes a bottom plate and parallel side plates. The several latching units are rotatably connected to a lower side of the side plate, a free end of the latching unit defines a latching portion. The side plate defines a latching slot corresponding to the latching portion, and when the latching unit is rotated to abut the side plate, the latching portion is latched in the latching slot and holds a hard disk drive strongly and stably in an receiving space defined by the bottom plate and the side plates. The electronic device is further disclosed.