An almanac (also spelled almanack, especially in Commonwealth English) is an annual publication containing tabular information in a particular field or fields often arranged according to the calendar. Astronomical data and various statistics are also found in almanacs, such as the times of the rising and setting of the sun and moon, eclipses, hours of full tide, stated festivals of churches, terms of courts, lists of all types, timelines, and so on.

When almanacs were first devised, people saw little difference between predicting the movements of the stars and tides, and predicting the future in the divination sense. Early almanacs therefore contained general horoscopes, as well as the more concrete information. One almanac, Poor Robin's Almanack parodied these horoscopes in its 1664 issue, saying "This month we may expect to hear of the Death of some Man, Woman, or Child, either in Kent or Christendom." This sort of almanac still exists as Old Moore's Almanac, although their more mainstream modern descendents are the Your Year in the Stars supplements in the New Year edition of some newspapers and magazines.

See also: List of almanacs, List of reference tables, Gazetteer

Almanac is also the title of an album by the band They Might Be Giants.