A sanitary washing device includes a nozzle, a valve unit, a casing, a water supply hose, and a water supply connection part. The nozzle is configured to discharge water toward an ano-genital region. 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 water supply hose is configured to supply water from the water supply source into the casing. The water supply hose is flexible. The water supply connection part connects the water supply hose and the valve unit. The casing has a concave portion recessed upward from a bottom surface of the casing. The concave portion has an upper surface and a side surface extending from the upper surface and facing backward or sideward. The water supply connection part is provided on the side surface of the concave portion.