Kasumigaura is a city located in the Ibaraki Prefecture of Japan. The city derives its name from the nearby Lake Kasumigaura and covers a total area of 156.60 square kilometers. As of July 2020, it had an estimated population of 40,254 residents living in 15,839 households.
The city is notable for having one of the longest names in Japan, a distinction it shares with Ichikikushikino and Tsukubamirai. Additionally, a significant portion of the city's territory is situated within the boundaries of the Suigō-Tsukuba Quasi-National Park.