Ritual washing in Judaism, or ablution, takes two main forms. A tevilah (טְבִילָה) is a full body immersion in a mikveh, and a netilat yadayim which is the washing of the hands with a cup.

References to ritual washing are found in the Hebrew Bible, and are elaborated in the Mishnah and Talmud. They have been codified in various codes of Jewish law and tradition, such as Maimonides's Mishneh Torah (12th century) and Joseph Karo's Shulchan Aruch (16th century.) These customs are most commonly observed within Orthodox Judaism. In Conservative Judaism, the practices are normative with certain leniencies and exceptions. Ritual washing is not generally performed in Reform Judaism.

The Hebrew Bible includes various regulations about bathing:

And also references to hand-washing:

Philo of Alexandria refers to ritual washing in the context of the Temple and Leviticus, but also speaks of spiritual "washing." At Qumran basins which served as baths have been identified, and among the Dead Sea scrolls texts on maintaining ritual purity reflect the requirements of Leviticus.