In astrology, a horoscope is a chart or diagram representing the positions of the Sun, Moon, planets, the astrological aspects, and sensitive angles at the time of an event, such as the moment of a person's birth. The word horoscope is derived from Greek words meaning "a look at the hours" (horoskopos, pl. horoskopoi, or "marker(s) of the hour.") Other commonly used names for the horoscope in English include astrological chart, astro-chart, celestial map, sky-map, star-chart, cosmogram, vitasphere, radical chart, radix, chart wheel, or simply chart. It is used as a method of divination regarding events relating to the point in time it represents and forms the basis of the horoscopic traditions of astrology.

In common usage, horoscope often refers to an astrologer's interpretation, usually through a system of Sun sign astrology or based upon calendar significance of an event, as in Chinese astrology. In particular, many newspapers and magazines carry predictive columns based on celestial influences in relation to the zodiacal placement of the Sun on the day of a person's birth, identifying the individual's Sun sign or "star sign." This system is distinct from horoscopes as traditionally employed, as only the zodiacal placement of the Sun is considered in interpretation . While this modern usage is perhaps the most popular in the colloquial lexicon, this article will focus primarily on the traditional concept.