Jagadguru Shri Chandrasekharendra Saraswati Shankaracharya Mahaswamigal (born in a Kannada Smartha family as Swaminathan Shasthri; 20 May 1894 – 8 January 1994) also known as the Sage of Kanchi or Mahaperiyava (meaning, "The great elder") was the 68th Jagadguru Shankaracharya of the Moolamnaya Saravjna Kanchi Kamakoti Peetham. Mahaperiyava's discourses have been recorded in a Tamil book titled "Deivathin Kural" (Voice of God).

Jagadguru Shri Chandrasekharendra Saraswati Mahaswamigal (born Swaminathan Shasthri) was born on 20 May 1894. He was brought up in the central part of the southern state of Tamil Nadu, Villupuram, South Arcot District. Kannada Smartha Brahmin Rig Vedic family that had migrated to Tamil Nadu generations earlier. Subrahmanya Sastri worked as a teacher having entered the educational service. His mother Mahalakshmi was also from a Kannada Brahmin family from the village of Eachangudi near Tiruvaiyaru. Swaminathan was the second child of his parents. His younger brother later became the great yogi Sivan SAR.

Swaminathan's upanayanam was performed in Tindivanam in 1905 and it was during his upbringing that he became well versed in the Vedas and started performing pujas. In 1906 the 66th Acharya of Kamakoti Pitha, Sri Chandrasekharendra Saraswati VI, was camping in Perumukkal, a small village near Tindivanam in observance of the Chaturmasya vrata. The 66th Acharya attained siddhi and died in Kalavai, only 1 week after ascending the position and Swaminathan's maternal cousin was installed as the 67th Acharya. The 67th Acharya had a fever, attained siddhi and died. Due to the unexpected turn of events, Swaminathan was installed as the next Acharya. Swaminathan ascended the Kanchi Kamakoti Peetham on Paraabhava Tamil Year Maasi Tamil Month Moolam Star in the year 1907 (13th February 1907) as the 68th Acharya with the Sannyasashrama nama Chandrasekharendra Saraswati.

As per the usual training given to the seers, he was well-trained in the Vedas, Puranas, various Hindu texts and ancient Indian literature. The Acharya was fifteen years old in 1909. For two years he studied under the pandits of the Matha at Kumbakonam. From 1911 to 1914 he studied in Mahendramangalam, a tiny village on the Northern bank of Akhanda Kaveri. The Acharya showed interest in subjects such as photography, mathematics and astronomy. He returned to Kumbakonam in 1914. The Court of Wards managed the Matha (or mutt) from 1911 to 1915 until he turned twenty-one in May 1915.

I had a bath at the Kumara Koshta Thirtha. A carriage of the Mutt had come there from Kalavai with the people to buy articles for the Maha Puja on the tenth day of the passing of the previous 66th Acharya. One of them, a hereditary maistry (mason) of the Mutt, asked me to accompany him. A separate cart was engaged for the rest of the family to follow me. During the journey, the maistry hinted to me that I might not return home and that the rest of my life might be spent in the Mutt itself. At first, I thought that my elder cousin had become the Head of the Mutt, it was his wish that I should live with him. But the maistry gradually clarified matters as the cart rolled on. The Acharya had a fever which developed into delirium and that was why I was separated from the family to be taken to Kalavai. I was stunned by this unexpected turn of events. I lay in a kneeling posture in the cart, shocked as I was, repeating “Rama… Rama,” the only prayer I knew. My mother and other children came sometime later only to find that instead of her mission of consoling her sister, she was placed in the state of having to be consoled. — Jagadguru Shri Chandrasekharendra Saraswati Shankaracharya Mahaswamigal

Mahaperiyava started spreading his knowledge in spiritual journeys across the Indian hinterland. These included devotional practices and daily rituals such as performing various Poojas and recitations of the Vedas. Iyengars (who were not part of the mutt), various sub castes and Abrahamic followers became his devotees. He carried the responsibility effortlessly and made simple practices for devotees to increase devotion, like chanting and writing the holy name of Rama. Devotees soon realized he was not a normal person and labelled him a Jagadguru (lit. the guru of the universe) for his help in rectifying their issues. Mahaperiyava dedicated his life to the deity Kamakshi in the premises where he was the spiritual guru, Kamakshi Amman temple. The temple is where the goddess herself came personally for devotion to Shiva.

Throughout his life, Mahaperiyava breathed and practised the Advaita philosophy of his guru, Adi Shankaracharya, the great Hindu philosopher and reformist. Mahaperiyava renovated multiple temples across India and increased the recitals of sacred texts like the Vishnu Sahasranāma (which was not allowed by women at the time). Mahaperiyava helped Vedic priests on their pronunciation of the holy Sanskrit texts and implemented rigorous Agama Sastra teachings describing cosmology, epistemology, philosophical doctrines, precepts on meditation and other topics. He also had a huge love towards Tamil language. He had many discourses with esteemed Tamil Scholars. He also bought in the practice of conducting the "Paavai Nonbu Padal Poti"(Margazhi month Thiruppavai and Thiruvempavai singing competition) for young children. He made radical social changes by allowing devotees inside the temple premises. The day India became independent on August 15th 1947, he gave a speech on the significance of the flag and the Ashoka Chakra in it.

He died without celebrating his centenary on 8 January 1994. His attainment of Videhamukti invited devotees to go beyond numerology and believe only the name of god in their lifespan. He was also considered an avatar of the Hindu deity Shiva ^{[by whom?]}.