水神（日语：すいじん或みずがみ）乃日本神道对于与水（主要是淡水水域）相关的神祇之总称。

对农耕民族而言，水是最重要的东西，尤其能左右该年的收获状况。一般日本民间普遍将水神与田神一同共祀，便是这个原因。至于在水源地祭祀之水神（有时称作水分神），则通常跟山神作链接。另外关于日常生活用的水，则在水井、汲水之处祭拜水神。常见的水神象征有河童、龙、蛇等动物，日本民间认为这些神使乃水神派遣而来。

Suijin(水神,water god) is the Shinto god of water in Japan. The term Suijin (literally water people or water deity) refers to the heavenly and earthly manifestations of the benevolent Shinto divinity of water. But it also refers to a wide variety of mythological and magical creatures found in lakes, ponds, springs and wells, including serpents (snakes and dragons), eels, fish, turtles, and the flesh-eating kappa. As The God of Water, Mizu no Kamisama, Mizugami, or Suijin, he is widely revered in Japan. He is a big part of Japanese culture and is often worshiped in temples.