A refrigeration cycle device is configured to be selectively switchable between an air-cooling first refrigerant circuit that causes refrigerant to flow out of a liquid-phase refrigerant outlet of a gas-liquid separator, and an air-heating second refrigerant circuit that causes the refrigerant to flow out of a gas-phase refrigerant outlet of the gas-liquid separator. In the refrigeration cycle device, an oil separator is disposed in a refrigerant passage that leads from a heat dissipation device to a first expansion valve. Thus, when the first refrigerant circuit is configured in the refrigeration cycle device, the refrigerant passing through the oil separator is in a single gas phase or in an almost gas phase, so that oil can be easily separated from the refrigerant. Furthermore, when the refrigerant circulates through the first refrigerant circuit, oil can be retained at a position other than the gas-liquid separator.