Beltane is the anglicized version of the Gaelic name for the month of May. In some areas, it is also the name of the festival that takes place on the first day of May.

As an ancient Gaelic holiday it was celebrated around May 1, the date also known as "May Day". Historically, this festival was celebrated in Ireland, Scotland and the Isle of Man. There were similar festivals held at the same time in the other Celtic countries of Wales, Brittany and the county of Cornwall. Beltane and Samhain were the leading terminal dates of the civil year in Ireland though the latter festival was the most important. The festival of Beltane survives in folkloric practices in the Celtic Nations and the diaspora, and has experienced a degree of revival in recent decades. Like the festival of Samhain (celebrated on October 31st), Beltane was also a time when the Otherworld was seen as particularly close at hand.

For the Celts, Beltane marked the beginning of the pastoral summer season when the herds of livestock were driven out to the summer pastures and mountain grazing lands. Great bonfires would mark a time of purification and transition, heralding in the season in the hope of a good harvest later in the year, and were accompanied with ritual acts to protect the people from any harm by otherworldly spirits.

Beltane is observed by Neopagans in various forms, and by a variety of names. As forms of Neopaganism can be quite different and have very different origins, these representations can vary considerably despite the shared name. Some celebrate in a manner as close as possible to how the Ancient Celts and Living Celtic cultures have maintained the traditions, while others observe the holiday with rituals taken from numerous other unrelated sources, Celtic culture being only one of the sources used.

Wiccans and Wiccan-inspired Neopagans celebrate a variation of Beltane as a sabbat, one of the eight solar holidays. Although the holiday may use features of the Gaelic Beltane (Bealtaine), such as the bonfire, it bears more relation to the Germanic May Day festival, both in its significance (focusing on fertility) and its rituals (such as maypole dancing). Some Wiccans celebrate 'High Beltaine' by enacting a ritual union of the May Lord and Lady.