In an indoor unit for an air-conditioning apparatus, a casing has an air inlet formed in an upper part and an air outlet formed below a front part. The casing accommodates a heat exchanger and fan. A horizontal airflow-direction louver is mounted pivotally inside the air outlet to guide airflow in a horizontally changeable manner. A vertical airflow-direction louver is mounted to cover the air outlet in a closed position and to guide airflow in a vertically changeable manner. An infrared sensor projects downward from the casing at a position in a horizontal end portion of the casing and in front of the air outlet. An airflow blocking portion is located behind the infrared sensor, and has a side wall on or beside one edge of the air outlet. The side wall is located closer to a center of the air outlet in the horizontal direction than the infrared sensor.