Provided is an indoor unit for an air-conditioning apparatus, which is capable of detecting a room temperature without impairing a design of the air-conditioning apparatus. The indoor unit for an air-conditioning apparatus according to the present invention includes: a housing having a rear surface mounted to a wall and having an air inlet and an air outlet formed therein; a heat exchanger and an air-sending device arranged on a main air passage extending from the air inlet to the air outlet; and a room temperature sensor configured to detect a temperature of an intake air. The housing has an air intake port from which air to be sent to the room temperature sensor is allowed to be taken, the air intake port being provided in a side surface adjacent to the rear surface. The room temperature sensor is arranged on an air passage connecting the air intake port and the main air passage. The air intake port is opened toward a rear surface side of the housing.