An outdoor unit for an air-conditioning apparatus, comprising: a heat exchanger including a plurality of heat exchanger units (10a, 10b), the plurality of heat exchanger units (10a, 10b) being vertically stacked and each including a long side portion, a short side portion, and a bent corner portion connecting the long side portion and the short side portion to each other; and a first regulating part regulating relative positions of ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other, the first regulating part regulating the relative positions of the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other by sandwiching inflow-surface portions and outflow-surface portions in an air flow direction of the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other in a range from a part of a corresponding one of the long side portions to a middle of a corresponding one of the bent corner portions continuous from the corresponding one of the long side portions, in the heat exchanger, deviation in the air flow direction, that lies between the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other being larger at the short side portions than at the long side portions through alignment by the first regulating part of the relative positions of the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other in the range from the part of the corresponding one of the long side portions to the middle of the corresponding one of the bent corner portions continuous from the corresponding one of the long side portions. a heat exchanger including a plurality of heat exchanger units (10a, 10b), the plurality of heat exchanger units (10a, 10b) being vertically stacked and each including a long side portion, a short side portion, and a bent corner portion connecting the long side portion and the short side portion to each other; and a first regulating part regulating relative positions of ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other, the first regulating part regulating the relative positions of the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other by sandwiching inflow-surface portions and outflow-surface portions in an air flow direction of the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other in a range from a part of a corresponding one of the long side portions to a middle of a corresponding one of the bent corner portions continuous from the corresponding one of the long side portions, in the heat exchanger, deviation in the air flow direction, that lies between the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other being larger at the short side portions than at the long side portions through alignment by the first regulating part of the relative positions of the ones of the plurality of heat exchanger units (10a, 10b) that are vertically adjacent to each other in the range from the part of the corresponding one of the long side portions to the middle of the corresponding one of the bent corner portions continuous from the corresponding one of the long side portions.