Litha or Midsummer refers to the period of time centered upon the summer solstice and the religious celebrations that accompany it. Midsummer-related holidays, traditions and celebrations are particularly important in Denmark, Finland and Sweden, but found also in other parts of Germanic Europe and elsewhere.

Midsummer is also sometimes referred to as Litha; stemming from Bede's De Tempore Rationum in which he gave the Anglo-Saxon names for the months roughly corresponding to June and July.

Litha, is one of the eight solar holidays or sabbats observed by Wiccans, though the New Forest traditions (those referred to as British Traditional Wicca) tend to use the traditional name Midsummer. It is celebrated on the Summer Solstice or close to it. The holiday is considered the turning point at which summer reaches its height and the sun shines longest. Among the Wiccan sabbats, Midsummer is preceded by Beltane and followed by Lughnasadh or Lammas.

Solstitial celebrations still center upon 24 June, which is no longer the longest day of the year, which is actually 21 June. In the Gregorian calendar, the solstice moves around a bit but in the long term it moves only about one day in 3000 years.