In Abrahamic religions, a messiah or messias (Hebrew: מָשִׁיחַ, romanized: māšīyaḥ; Greek: μεσσίας, messías; Arabic: مسيح, masîḥ; lit. 'the anointed one') is a saviour or liberator of a group of people. The concepts of mashiach, messianism, and of a Messianic Age originated in Judaism, and in the Hebrew Bible, in which a mashiach is a king or High Priest traditionally anointed with holy anointing oil.

Ha-mashiach (המשיח, 'the Messiah'), often referred to as melekh mashiach (מלך המשיח, 'King Messiah'), is to be a Jewish leader, physically descended from the paternal Davidic line through King David and King Solomon. He is thought to accomplish predetermined things in a future arrival, including the unification of the tribes of Israel, the gathering of all Jews to Eretz Israel, the rebuilding of the Temple in Jerusalem, the ushering in of a Messianic Age of global universal peace, and the annunciation of the world to come.

The Greek translation of Messiah is Khristós (Χριστός), anglicized as Christ. It occurs 41 times in the Septuagint and 529 times in the New Testament. Christians commonly refer to Jesus of Nazareth as either the "Christ" or the "Messiah", believing that the messianic prophecies were fulfilled in the mission, death, and resurrection of Jesus and that he will return to fulfill the rest of messianic prophecies. Moreover, unlike the Judaic concept of the Messiah, Jesus Christ is additionally considered by Christians to be the Son of God.

In Islam, Jesus (Arabic: عيسى, romanized: Isa) is held to have been a prophet and the Messiah sent to the Israelites, who will return to Earth at the end of times along with the Mahdi, and defeat al-Masih ad-Dajjal, the false Messiah. In Ahmadiyya theology, these prophecies concerning the Mahdi and the second coming of Jesus are believed to have been fulfilled in Mirza Ghulam Ahmad (1835–1908), the founder of the Ahmadiyya Movement, wherein the terms Messiah and Mahdi are synonyms for one and the same person.

In controversial Chabad messianism, Yosef Yitzchak Schneersohn (r. 1920–1950), sixth Rebbe (spiritual leader) of Chabad Lubavitch, and Menachem Mendel Schneerson (1902–1994), seventh Rebbe of Chabad, are Messiah claimants.