Provided is a refrigerating machine oil composition including a base oil which contains at least one substance selected from the group consisting of monoether compounds, alkyleneglycol diethers, and polyoxyalkyleneglycol diethers having an average repetition number of an oxyalkylene group of 2 or less as a main component, and has a kinematic viscosity at 40° C. of 1 to 8 mm2/s. The refrigerating machine oil composition is preferably applied to refrigerators whose sliding parts are composed of an engineering plastic or provided with an organic coating film or an inorganic coating film. The refrigerating machine oil can improve energy-saving performance due to its low viscosity, has high sealing property and excellent load capacity, and is suitably used in various refrigeration applications, especially in closed-type refrigerators.