Shani (शनि, Śani / Śanaiśchara) refers to the planet Saturn.
He is the god of Karma (कर्म), justice and retribution in the Hindu religion and delivers results to all, depending upon their thoughts, speech and deeds Karma (कर्म), which could be a positive or negative impact on their lives.
He also signifies spiritual asceticism, penance, discipline and conscientious work.

Shani (शनि, Śani / Śanaiśchara) is also a male Hindu deity in the Puranas (पुराण / a vast genre of Indian literature about a wide range of topics, particularly about legends and other traditional lore), whose iconography consists of a black figure carrying a sword or danda (sceptre), and sitting on a vulture.

He married twice, first being Neela (नीला), the personification of the Blue Sapphire gemstone, and Manda (मान्दा, Māndā), a Gandharva princess.
- In Hinduism, Neela (नीला) is known as Neelima (नीलिमा) or Neelamratna (नीलमरत्न).
She is the first consort and the chief wife of Shani (शनि) and mother of Kuligna (कुलिग्ना).
She balances and increases power of Shani (शनि) and is the goddess of the gemstone sapphire.
Her son Kuligna (कुलिग्ना) is a Rishi (ऋषि / term for an accomplished and enlightened person).
Her husband, Shani (शनि), also married a Gandharva lady, Dhamini (धामिनी, Dhāminī / मान्दा, Māndā).
- In Hinduism, Manda (मान्दा, Māndā) or Dhamini (धामिनी, Dhāminī) is the second consort of Shani (शनि) and mother of Gulikan (गुलिकनी).
She is a Gandharva princess (गन्धर्व / Gandharva is a class of celestial beings whose males are divine singers and females are divine dancers) and the most famous chief consort of Shani (शनि).
She is the goddess of Kalā (चौसठ कलाएँ / Kalā means performing art in Sanskrit).
Her Nrtya Dance (नृत्य) can attract anyone in the whole Brahmand (ब्रह्मांड / Universe).
Manda (मान्दा) is mentioned as divine regent of Planet Saturn (शनि, Shani) in India.

Shani (शनि, Śani / Śanaiśchara) is also known as: Shanishvara (शनीश्वरा), Chhayasutha (छायसुथा), Pingala (पिंगला), Kakadhwaja (काकड़ध्वज), Konastha (कोणस्थ), Babhru (बभ्रु), Krishna (कृष्ण), Roudhraantak (रौद्रान्तक), Yam (यम), Sauri (सौरि), Mand (मंड) and Pipplayshraya (पिपल्याश्रय).

Shani (शनि, Śani / Śanaiśchara) is a deity in medieval era texts, who is considered inauspicious and is feared for delivering misfortune and loss to those who deserve it.
He is also capable of conferring boons and blessings to the worthy, depending upon their karma (कर्म).

He is also believed to be the greatest teacher who rewards the righteous acts and punishes those who follow the path of evil, Adharma (अधर्म / Adharma is the Sanskrit antonym of dharma and it means "that which is not in accord with the dharma") and betrayal. 

In medieval Hindu literature, he is mainly referred to as the son of Surya (रवि, Ravi) and Chhaya (साया, Shadow), or in few accounts as the son of Balarama (बलराम / the elder brother of कृष्ण, Krishna) and Revati (रेवती).
In these references, he has alternate names include: Ara (आरा), Kona (कोना) and Kroda (करोडा).

As per the Hindu texts, 'peepal' or fig tree is the abode of Shani (while other texts associate the same tree with वासुदेव, Vasudeva).
- According to Hindu scripture, Vasudeva (वसुदेव), also called Ānakadundubhii (अनाकादुंदुभि / "Drum", after the sound of drums heard at the time of his birth), is the father of the Hindu deities Krishna (कृष्ण), Balarama (बलराम) and Subhadra (सुभद्रा).

In 2013, a 20-foot-tall statue of Lord Shani (शनि, Shani, Śani / Śanaiśchara) was established at Yerdanur (यरदनूर) in the mandal of Sangareddy (संगारेड्डी), Medak district (मेडक), Telengana (तेलंगाना), nearly 40 kilometers from Hyderabad city (हैदराबाद).
It was carved from a Monolith and weighs about nine tonnes.

Shani (शनि, Śani / Śanaiśchara) as a planet appears in various Hindu Astronomical texts in Sanskrit (संस्कृत), such as:
- Aryabhatiya (आर्यभटीय, 5th Century) by the major mathematician-astronomer from the classical age of Indian Mathematics and Indian Astronomy, Aryabhata (आर्यभट).
- Romaka (रोमाका, 6th Century) by the astronomer, Latadeva (लतादेव), based in Byzantine Astronomy.
- Pancasiddhantika (पैनकासिधांटिका, 6th Century) by the polymath astronomer, Varahamihira (वराहमिहिर).
- Khandakhadyaka (खण्डखाद्यक, 665 AD) by the mathematician and astronomer, Brahmagupta (ब्रह्मगुप्त).
- Sisyadhivrddida (सिसियादहिर्डिडा, 8th Century) by the mathematician, astronomer and astrologer, Lalla (लल्ल).
These texts present Shani (शनि) as one of the planets and estimate the characteristics of the respective planetary motion.
Other texts such as Surya Siddhanta (सूर्यसिद्धान्त), dated to have been complete sometime between the 5th Century and 10th Century, present their chapters on various planets with Deity Mythologies.

Shani (शनि) is the basis for Shanivara (शनिवार:) - one of the seven days that make a week in the Hindu calendar.
This day corresponds to Saturday - after Saturn - in the Greco-Roman convention for naming the days of the week.
Shani (शनि) is considered to be the most malefic planet that brings restrictions and misfortunes.

Shani (शनि) is part of the Navagraha (नवग्रह / "Nine Celestial Bodies") in Hindu zodiac system, considered malefic, associated with spiritual asceticism, penance, discipline and conscientious work.
The role and importance of the Navagraha (नवग्रह) developed over time with various influences.
Deifying planetary bodies and their astrological significance occurred as early as the Vedic period (वैदिक) and was recorded in the Vedas (वेदों).
The earliest work of astrology recorded in India is the Vedanga Jyotisha (वेदांग ज्योतिष), which began to be compiled in the 14th century BCE.
It was possibly based on works from the Indus Valley Civilization as well as various foreign influences. Babylonian astrology which was the first astrology and calendar to develop, and was adopted by multiple civilizations including India.
Saturn and various classical planets were referenced in the Atharvaveda (अथर्ववेद:) around 1000 BCE.
The Navagraha (नवग्रह) was furthered by additional contributions from Western Asia, including Zoroastrian and Hellenistic influences.
The Yavanajataka (यवनजातक:), or 'Science of the Yavanas', was written by the Indo-Greek named "Yavanesvara" (यवनेसवारा / "Lord of the Greeks") under the rule of the Western Kshatrapa King Rudrakarman I (रुद्रदामन).
The Yavanajataka (यवनजातक:) written in 120 CE, is often attributed to standardizing Indian astrology.
The Navagraha (नवग्रह) would further develop and culminate in the Shaka era with the Saka or Scythian, people. Additionally the contributions by the Saka people would be the basis of the Indian national calendar, which is also called the Saka calendar.
The Hindu calendar is a Lunisolar calendar which records both lunar and solar cycles.
Like the Navagraha (नवग्रह), it was developed with the successive contributions of various works.

Planet Shani (शनि) rules over both zodiac signs, Capricorn (मकर राशि, Makar raashi) and Aquarius (कुंभ राशि, Kumbh raashi), two of the twelve constellations in the zodiac system of Hindu astrology.
If Shani (शनि) rules over your zodiac sign, it is said you must wear a ring with a stone made of Blue Sapphire.