The Muktika canon of 108 Upanishads is headed by 10 Mukhya Upanishads. These are the ten oldest Upanishads, known to and commented upon by the 9th century scholar Shankara. Sanskrit means "principal", "chief", or "eminent". The ten Mukhya Upanishads probably all predate the Common Era, and they are accepted as śruti by all Hindus. They are listed with their associated Veda ():

1. , (ŚYV) "The Inner Ruler"
2. (SV) "Who moves the world?"
3. (KYV) "Death as Teacher"
4. , (AV) "The Breath of Life"
5. (AV) "Two modes of Knowing"
6. (AV) "Consciousness and its phases"
7. (KYV) "From Food to Joy"
8. , (ṚV) "The Microcosm of Man"
9. (SV) "Song and Sacrifice"
10. (ŚYV)

Linguistically, the oldest of these (Bṛhadāraṇyaka, Chāndogya) belong to the "Brahmana" period of Vedic Sanskrit, predating Panini. A middle layer (Kaṭha) belongs to the "Sutra" period of late Vedic Sanskrit, roughly contemporary with Panini, and the youngest are in early Classical Sanskrit, approximately contemporary with the Bhagavad Gita (roughly dating to the period from the 4th century BC to the beginning of the Common Era, or the Mauryan period).

See also

• Samanya Vedanta Upanishads