Yom Kippur is the holiest day of the year in Judaism and Samaritanism. It occurs annually on the 10th of Tishrei, corresponding to a date in late September or early October.

In Judaism, the Yom Kippur Temple service was a special sacrificial service performed by the High Priest of Israel on the holiday of Yom Kippur, in the Temple in Jerusalem. Through this service, according to the Bible, the Jewish people would achieve atonement for their sins once each year. The service is notable as the only time in the year any person was allowed to enter the Holy of Holies, and is the source of the term scapegoat.