In Jewish religious law (halakha), the laws of yichud (Hebrew: איסור ייחוד‎ issur yichud, prohibition of seclusion) prohibit seclusion in a private area of a man and a woman who are not married to each other. Such seclusion is prohibited in order to prevent the two from being tempted or having the opportunity to commit adulterous or promiscuous acts. A person who is present in order to prevent yichud is called a shomer.

The laws of yichud are typically followed in Orthodox Judaism. Adherents of Conservative and Reform Judaism do not generally abide by the laws of yichud.

The term "yichud" also refers to a ritual during an Ashkenazi Jewish wedding in which the newly married couple spends a period secluded in a room by themselves. In earlier historical periods, as early as the talmudic era,[1] the marriage would be consummated at this time, but that practice is no longer current.