岛原之乱（1637年—1638年 寛永14年10月25日）是日本历史上江户幕府期间的一次的一揆抗争，参加者很多是基督徒。此战为幕末之前的最后一次内战。

天主教自1549年由耶稣会教士方济各·沙勿略首次传入日本后，人数迅速发展，特别是在九州、京都和江户地区。位于九州西部的岛原在信奉基督教的大名小西行长影响下，传教活动旺盛，在关原之战，所领改由寺泽广高所管领。

天主教的扩张引起传统的佛教和神道教反对；1587年，丰臣秀吉正式驱逐传教士，宣布基督教是邪教。然而教徒数量却继续增加，到17世纪初信众已达70万人。这时正值德川幕府准备统一日本，信奉天主教的地方诸侯成为政府特别征讨的对象，1614年幕府领令所有人必须弃教。

The Shimabara Rebellion(島原の乱,Shimabara no ran) was an uprising in southwestern Japan lasting from December 17, 1637, to April 15, 1638, during the Edo period. It largely involved peasants, most of them Catholic Christians.

It was one of only a handful of instances of serious unrest during the relatively peaceful period of the Tokugawa shogunate's rule. In the wake of the Matsukura clan's construction of a new castle at Shimabara, taxes were drastically raised, which provoked anger from local peasants and rōnin (samurai without masters). Religious persecution of the local Catholics exacerbated the discontent, which turned into open revolt in 1637. The Tokugawa Shogunate sent a force of over 125,000 troops to suppress the rebels and, after a lengthy siege against the rebels at Hara Castle, defeated them.