The invention discloses a wall-mounted air conditioner including an indoor unit. The indoor unit includes a front housing and a rear housing forming housing, the housing is provided with main air intake portions, heat exchangers are disposed inside the housing, both orthographic projection of the front housing and the rear housing are circular or approximately circular, the rear housing is located within a limiting area of the front housing, a surface of the front housing is an arc surface in which an upper portion and a lower portion contract backwards and a middle portion protrudes forwards, and a lower portion of the front housing is provided with an air outlet. The wall-mounted air conditioner according to the invention improves a structure of an existing wall-mounted air conditioner and can output air backwards, thereby ensuring fast flow and temperature adjustment of indoor air.