An outdoor unit for an air-conditioning apparatus according to the present disclosure includes a heat exchanger comprised of an upper heat exchanger and a lower heat exchanger that are arranged in an up-down direction, an accumulator configured to store refrigerant, a casing, an inside of which is partitioned by a partition plate into an air-sending chamber accommodating the heat exchanger and a machine chamber accommodating the accumulator, and a fixing component configured to be fixed to the heat exchanger and the accumulator so that the accumulator is fixed to the heat exchanger, wherein the fixing component is fixed to both of the upper heat exchanger and the lower heat exchanger.