Jewish religious movements, sometimes called "denominations", include diverse groups within Judaism which have developed among Jews from ancient times. Today in the west, the most prominent divisions are between traditionalist Orthodox movements and modernist movements such as Reform Judaism originating in late 18th century Europe, Conservative originating in 19th century Europe, and other smaller ones, including the Reconstructionst and Renewal movements which emerged later in the 20th century in the United States.

Judaism is an Abrahamic, monotheistic, and ethnic religion, comprises the collective spiritual, cultural, and legal traditions of the Jewish people. Contemporary Judaism having originated as an organized religion in the Middle East during the Bronze Age, and evolved from Yahwism, the cultic polytheistic religious movement of ancient Israel and Judah, around the 6th/5th century BCE, and is thus considered to be one of the oldest monotheistic religions. Along with Samaritanism, to which it is closely related, Judaism is one of the two oldest Abrahamic religions.