The seat air conditioner configured to supply conditioning air to a seat in a vehicle cabin includes a refrigeration cycle, an air blower, and a conditioning air supply unit. The refrigeration cycle includes a compressor that compresses and discharges a refrigerant, a heat emitting portion that emits heat of the refrigerant discharged from the compressor to generate a warm air, a decompressor that decompresses the refrigerant flowing out of the heat emitting portion, and a heat absorbing portion that evaporates the refrigerant decompressed by the decompressor to generate a cold air. The air blower blows air to exchange heat with the refrigerant. The conditioning air supply unit supplies each of the warm air generated by the heat emitting portion and the cold air generated by the heat absorbing portion as the conditioning air to the seat.