圣行（阿拉伯语：سنة）是阿拉伯语用语，指习惯或惯常做法。穆斯林以此用语来描述伊斯兰教先知穆罕默德的言行习性。

记录圣行是阿拉伯的传统，人们皈依了伊斯兰教后，便将这个传统带到伊斯兰教里。

穆罕默德圣行包括他的具体言词、行为及习惯，对伊斯兰教的灵性作用重大，圣行展示了与朋友、家庭及政府的生活方式。

伊斯兰教法、马利克·阿本·阿纳斯（Malik ibn Anas）及哈纳斐学派（Hanafi）认为圣行与圣训有所区别。马利克·阿本·阿纳斯拒绝接纳圣训，他认为圣训违反了「麦地那人民既定的习惯」。圣行被认为是穆罕默德所相信的事物，不论是暗示或默示，这些圣行被他的同伴记录下来并成为当今的圣训。

Sunnah (sunnah, سنة, Arabic: [sunna], plural سنن sunan [sunan]) is the verbally transmitted record of the teachings, deeds and sayings, silent permissions (or disapprovals) of the Islamic prophet Muhammad, as well as various reports about Muhammad's companions. Along with the Quran (the holy book of Islam), the Sunna makes up the two primary sources of Islamic theology and law. The Sunna is also defined as "a path, a way, a manner of life"; "all the traditions and practices" of the Islamic prophet that "have become models to be followed" by Muslims.