A variable capacity scroll compressor includes a fixed scroll. The fixed scroll of the compressor includes a bypass flow path configured to connect a suction unit to a compression unit, a cylinder space provided on the bypass flow path, and an on/off valve disposed to be movable back and forth in the cylinder space to open/close the bypass flow path according to a difference between a discharge pressure of the discharge unit and a suction pressure of the suction unit. Thus a capacity of the compressor may be reduced by connecting the suction unit to the compression unit under a low load condition in which a difference between a discharge pressure and a suction pressure is relatively less.