Hatsushima (初島) is an island in Sagami Bay, Japan. Administratively, it is part of the city of Atami, Shizuoka Prefecture, from which it can be reached by ferry. The island is approximately 10 kilometres from the ferry landing in downtown Atami. The island is inhabited, with the population mostly residing on the northern side of the island. As of 2018, the island had a population of 193 people in 114 households.