Libra (♎︎) is the seventh astrological sign in the zodiac. It spans 180°–210° celestial longitude. The Sun transits this sign on average between September 23 and October 23. The symbol of the scales is based on the Scales of Justice held by Themis, the Greek personification of divine law and custom. She became the inspiration for modern depictions of Lady Justice. The ruling planet of Libra is Venus along with Taurus. Libra is the only zodiac sign that is represented by an object; the other eleven signs are represented by either an animal or a mythological character.

In Western astrology, astrological signs are the twelve 30-degree sectors that make up Earth's 360-degree orbit around the Sun. The signs enumerate from the first day of spring, known as the First Point of Aries, which is the vernal equinox. The astrological signs are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. The Western zodiac originated in Babylonian astrology, and was later influenced by the Hellenistic culture. Each sign was named after a constellation the sun annually moved through while crossing the sky. This observation is emphasized in the simplified and popular sun sign astrology. Over the centuries, Western astrology's zodiacal divisions have shifted out of alignment with the constellations they were named after by axial precession of the Earth while Hindu astrology measurements correct for this shifting. Astrology was developed in Chinese and Tibetan cultures as well but these astrologies are not based upon the zodiac but deal with the whole sky.