Scorpio (♏︎; Ancient Greek: Σκορπιός, romanized: Skorpiós, Latin for "scorpion") is the eighth astrological sign in the zodiac, originating from the constellation of Scorpius. It spans 210–240° ecliptic longitude. Under the tropical zodiac (most commonly used in Western astrology), the Sun transits this sign on average from October 23 to November 21. Depending on which zodiac system one uses, someone born under the influence of Scorpio may be called a Scorpio or Scorpionic.

Scorpio is one of the three water signs, the others being Cancer and Pisces. It is the third fixed sign, after Taurus and Leo. Scorpio is also considered a negative or feminine sign. According to The Astrology Bible, Scorpio's colors are deep red, maroon, black, and brown.

According to Greek mythology, its representation as a scorpion is related to the Greek legend of Orion and how a giant scorpion stung him to death (said to be why Orion sets as Scorpius rises in the sky). Another Greek myth recounts how a scorpion caused the horses of the Sun to bolt, when they were being driven by the inexperienced youth, Phaethon.