Abstract: Disclosed are an air conditioner indoor unit and an air conditioner. The air conditioner indoor unit includes a housing, a volute assembly, an air deflector and a louver assembly. The housing is provided with an air outlet and the volute assembly is disposed in the housing. The volute assembly includes an upper volute and a lower volute forming an air outlet duct communicating with the air outlet therebetween. The air deflector is rotatably mounted at the air outlet to open or close the air outlet, and a middle portion of at least one end of the air deflector in a length direction is rotatably connected to the housing through a rotation shaft, to make the air deflector have an upward-opening state in which the air deflector is rotated around the rotation shaft to bring a lower side of the air deflector to come close to the upper volute and a downward-opening state in which the air deflector is rotated around the rotation shaft to bring an upper side of the air deflector to come close to the lower volute.