The Mōri clan was a Japanese samurai clan descended from Ōe no Hiromoto. Ōe no Hiromoto was descended from the Fujiwara clan. The family's most illustrious member, Mōri Motonari, greatly expanded the clan's power in Aki Province. During the Edo period his descendants became daimyō of the Chōshū Domain under the Tokugawa shogunate. After the Meiji Restoration with the abolition of the han system and daimyō, the Mōri clan became part of the new nobility.

This is a list of Japanese clans. The old clans (gōzoku) mentioned in the Nihon Shoki and Kojiki lost their political power before the Heian period, during which new aristocracies and families, kuge, emerged in their place. After the Heian period, the samurai warrior clans gradually increased in importance and power until they came to dominate the country after the founding of the first shogunate.