Śāṇḍilya (Sanskrit: शाण्डिल्य) was the name of at least two prominent rishis. One of the rishis was the progenitor of the Sandilya gotra.
The name was derived from the Sanskrit words śaṇ, full and dilam, the moon, with the derivative ya added, meaning the one of the full moon, thereby implying a priest or a descendant of the Moon God.
One rishi was a son of the sage Asita and grandson of the rishi Kashyapa, and the founder of the Śāṇḍilya gotra. Brihadaranyaka Upanishad states that he was a disciple of Vaatsya rishi. His other Acharyas include Kaushika, Gautama Maharishi, Kaishorya Kaapya, Vatsya Vaijavap, and Kushri. His disciples include Kaudinya, Agnivesa, Vatsya Vamakakshayan, Vaishthapureya, and Bharadwaj.  He was also the composer of the Śāṇḍilya Upanishad. According to theBhagavata Purana, he was instrumental in settling certain metaphysical doubts of King Parikshit of Hastinapura and King Vajra of Dwaraka.
Shandilya was a son of the sage Vasistha, had his hermitage in the Shāradāvanam, or forest of Sharada, of a village in the Bolair Valley of Kashmir. The village has been identified with the modern town of Sharda, on the banks of the River Kishanganga, in Pakistan Occupied Kashmir, India. The goddess Sharada is said to have manifested herself to him, here, after severe penance by him, to confer upon him his yagnopaveetham, an event that was commemorated in the temple ofSharada Peeth in the town.
The particular gotra had been migrated from swarasat land near Kanouj.
The History as written by contemporary writer "Kallahan" has indicated that there was a clan with a gotra called "Shandilya" migrated from upperdelta os river swaraswati, to Janapada of Aryasthan.
The later history of Saka 1001 has identified that Syamal varama had invited five Brahmin to perform special ritual for worshiping varun to mitigate famine in his kingdom.
These pancha gotra Brahmin settled in different part of Bengal.
The Brahmin of Shandilya gotra settled in Kotalpara.
He is one of the prominent Kulin Brahmin of special clan called "Pachiyatta Vaidik Brahmin".
"In Haryana Shandilya are known as Shandily Ritwal Brahmana's Found In Alipur Khalsha, Kohand, Jawara, Bahri-Bghain & Area of Radour. They are in God Brahmana's in Haryana".
Some of them have even recently migrated to Mumbai.