A sanitary washing device includes a nozzle, a valve unit, a casing, and a toilet seat. The nozzle is configured to discharge water toward an ano-genital region of a human body. The valve unit is provided on a pipe line between a water supply source and the nozzle. The valve unit includes an electromagnetic valve. The casing stores the nozzle and the valve unit. The toilet seat is pivotally supported to be rotatable with respect to the casing. A heater is provided inside the toilet seat. At least a portion of the valve unit is disposed below the toilet seat.