Walpurgis Night is the English translation of Walpurgisnacht, one of the German names for the night of 30 April, so called because it is the eve of the feast day of Saint Walpurga, an 8th-century abbess in Germany. In German folklore Walpurgisnacht, also called Hexennacht (literally "Witches' Night"), is believed to be the night of a witches' meeting on the Brocken, the highest peak in the Harz Mountains, a range of wooded hills in central Germany between the rivers Weser and Elbe.

The first known written occurrence of the English translation 'Walpurgis Night' is from the 19th century.

Local variants of Walpurgis Night are observed across Europe in the Netherlands, Germany, the Czech Republic, Sweden,Lithuania, Latvia, Finland and Estonia. In the United States, Walpurgisnacht is one of the major holidays celebrated withinLaVeyan Satanism and is the anniversary of the founding of the Church of Satan