Scorpio is the eighth astrological sign in the Zodiac, originating from the constellation of Scorpius. Scorpio is considered a "feminine", negative (introverted) sign by most modern astrologers. It is also considered a water sign and one of the four fixed signs. Traditionally, the planet Mars has been considered to be the ruler of Scorpio. Also, since its discovery, Pluto has been considered a modern ruler of this sign. As the eighth sign in the zodiac, Scorpio is associated with the astrological eighth house.

Individuals born when the Sun is in this sign are considered Scorpio individuals. Under the tropical zodiac, the Sun enters Scorpio on October 23 and exits on November 21. Under the sidereal zodiac, it is currently there roughly from November 16 through December 15. The Sanskrit name of Scorpio in Hindu astrology is Vrścika.

Astrologically, Scorpio is sometimes represented by an eagle or a phoenix, though this depiction is rare.

Generally, Scorpio is considered compatible with same element signs, Cancer, Pisces and Scorpio itself. These signs share a watery demeanor and are believed to relate with each other on that merit.

There are many variables that determine compatibility in astrology, such as birth dates, birth months, birth years, position of a sign within the Sun, the Moon, Stars, etc. The signs listed as compatible with Scorpio do not reflect an individual profile or individual reading as interpreted within astrology. They instead reflect a general guideline and reference to compatibility as dictated by variables such as Qualities and Elements within the Zodiac. The branch of astrology dealing with interpersonal compatibilities is called Synastry.