Samurai (侍) were the hereditary military nobility and officer caste of medieval and early-modern Japan from the late 12th century until their abolition in the 1870s during the Meiji era. They were the well-paid retainers of the daimyo, the great feudal landholders. They had high prestige and special privileges.

During certain times in history, they wore two swords and had kiri-sute gomen, the right to kill anyone of a lower class in certain situations. Some important samurai and other figures in Japanese history wanted others to believe all of them engaged combatants using bushido codes of martial virtues and followed impractical cultural ideals about what samurai should act like.

Though they had predecessors in earlier military and administrative officers, the samurai truly emerged during the Kamakura shogunate, ruling from c.1185 to 1333. They became the ruling political class, with significant power but also significant responsibility. During the 13th century, the samurai proved themselves as adept warriors against the invading Mongols. During the peaceful Edo period, 1603 to 1868, they became the stewards and chamberlains of the daimyo estates, gaining managerial experience and education.

In the 1870s, samurai families comprised 5% of the population. As modern militaries emerged in the 19th century, the samurai were rendered increasingly obsolete and very expensive to maintain compared to the average conscript soldier. The Meiji Restoration ended their feudal roles, and they moved into professional and entrepreneurial roles. Their memory and weaponry remain prominent in Japanese popular culture.