Shakti (Devanagari: शक्ति, IAST: Śakti; lit. 'energy, ability, strength, effort, power, might, capability') in Hinduism, is the "Universal Power" that underlies and sustains all existence. Conceived as feminine in essence, Shakti as devi refers to the personified energy or power of a male deity, often personified as the female consort of the given Hindu god.

In Tantric Shaktism, Shakti is the foremost deity, akin to Brahman. In Puranic Hinduism, Shiva and Shakti are the masculine and feminine principles that are complementary to each other. The male deity is purusha, pure consciousness, which creates the universe through the female creative energy of Shakti, which is prakriti, 'nature'.

The term Shakta is used for the description of people associated with Shakti worship. The Shakta pithas are shrines, which are believed to be the sacred seats of Shakti.

According to the Monier-Williams dictionary, the term Shakti (Śakti) is the sanskrit feminine word-meaning "energy, ability, strength, effort, power, might, capability"—thereby implying "capacity for" doing something, or "power over" anything. Shakti is also considered a feminine noun of the linguistic term Sanskrit. Though the term Shakti has broad implications, it mostly denotes "power or energy, which is feminine", and is also a name by which goddesses are referred to.

Much has been written in an effort to describe, define and delineate the principle of Shakti, which is held as the "most complex" goddess related theological concept. Shakti is primarily identified with the feminine and with the numerous Hindu goddesses, who are seen as "tangible" expressions-visible personifications of the intangible Shakti. Such an ideation for Shakti took place over many centuries. The concept of Shakti also includes the maternal spiritual histories and experiences transmitted generationally from a maternal elder.

Metaphysically, Shakti refers to "energetic principle" of the Ultimate reality—which is ideated as "primordial power". Shakti is believed to constitute such important factors as: "cit (consciousness, intelligence), ananda (joy, bliss), iccha (will), jnana (knowledge), and kriya (action)". In the study of Indian religions and their associated philosophies, one finds terms that combine Shakti with other concepts, giving rise to various expressions, such as; "adya Shakti (primal energy, primordial force), cit Shakti or vacya Shakti (the energy of consciousness), vacaka Shakti (manifested consciousness), and para Shakti (supreme energy, cause of all)"—all of which, by their association with Shakti, indicate that the respective concept is essentially feminine.

In classical Indian thought, Shakti is characterized as the divine principle in human, the creatrix of spiritual intuition and comprehension. Relatedly the term Shakta (Sanskrit: शक्त, Śakta) is used for people and customs associated with Shakti worship. The term Shakta became popular from the ninth-century onwards, before that the term Kula or Kaula, which referred to clans of female ancestry, besides to the menstrual and sexual fluids of females, was used to describe Shakti believers.

Archaeological excavations have revealed that practices of Mother goddess worship existed all over the world in ancient times. One of the earliest representation of mother goddess dates back to the Upper paleolithic period in Europe 20,000 years ago. Though goddess worship cults prevailed since antiquity in India, they gained popularity in the post Gupta era (6th century CE), mostly due to their esoteric practices. Apart from the Indian sculptures, the Vedas to the Tantras via the Puranas, constitute the major literary sources that trace the development of the goddess belief system.