A heating device includes a conveyor configured to convey a sheet onto which a liquid is applied in a conveyance direction, an irradiator including a light emitter on an irradiation surface of the irradiator, the light emitter configured to emit light onto the sheet to heat the sheet with the light, a channel plate between the conveyor and the irradiation surface of the irradiator, an airflow generator configured to generate an airflow along the irradiation surface between the irradiation surface of the irradiator and the channel plate, and a suction device configured to suck and discharge the airflow in a direction from the irradiation surface of the irradiator toward the conveyor.