弥赛亚（天主教汉译作默西亚；希伯莱语：מָשִׁיחַ‎；亚拉姆语：משיחא；阿拉伯语：المسيح‎，伊斯兰教汉译作麦西哈，景教译弥施诃），基督宗教术语，意指受上帝指派，来拯救世人的救主。 基督教主张“拿撒勒人耶稣就是弥赛亚，因为耶稣的出现，应验了许多旧约圣经中的预言”，伊斯兰教也认同耶稣就是弥赛亚，称他为"麦西哈尔撒"；而犹太教信徒则予以否认，并仍然期待他们心中的弥赛亚来临。

一些被指为异端和普遍认为是邪教的教派，其创办人也常以弥赛亚自居。例如麻原彰晃、文鲜明、又吉耶稣等。

A messiah (literally, "anointed one") is a saviour or liberator of a group of people, most commonly in the Abrahamic religions. In the Hebrew Bible, a messiah (Hebrew: מָשִׁיחַ, Modern mashiaẖ, Tiberian māšîăḥ) is a king or High Priest traditionally anointed with holy anointing oil. However, messiahs were not exclusively Jewish, as the Hebrew Bible refers to Cyrus the Great, king of Persia, as a messiah for his decree to rebuild the Jerusalem Temple.