Midsummer may simply refer to the period of time centered upon the summer solstice, but more often refers to specific European celebrations that accompany the actual solstice, or that take place on a day between June 21 and June 24, and the preceding evening. The exact dates vary between different cultures. Midsummer is especially important in the cultures of Scandinavia and Latvia where it is the most celebrated holiday apart from Christmas.

European midsummer-related holidays, traditions, and celebrations are pre-Christian in origin. They are particularly important in Northern Europe - Sweden, Norway, Denmark, Estonia, Finland, Latvia and Lithuania – but are also found in Germany, Ireland, parts of Britain (Cornwall especially), France, Italy, Malta, Portugal, Spain, Ukraine, other parts of Europe, and elsewhere - such as Canada, the United States, Puerto Rico, and also in the Southern Hemisphere (mostly in Brazil, Argentina and Australia), where this imported European celebration would be more appropriately called Midwinter.