A linear compressor is provided that includes a cylinder having a compression space for refrigerant therein, a piston that linearly reciprocates inside the cylinder in an axis direction to compress the refrigerant, and a frame having a mounting hole so that one end of the cylinder may be mounted thereon and a deformation prevention portion in some section around the mounting hole brought into contact with the one end of the cylinder. Even if a size of the cylinder is increased and a size of the frame limited, the frame is provided with enough strength to support the cylinder, thereby reducing fastening deformations and improving operation reliability.