Dr. K.C.Varadachari was born at Munulapudi Agraharam a small village near Tiruchanoor a temple town of Sri. Padmavathi Ammavaru on 14th August 1902, in the asterism of Moola and Vrschika Lagna. His father, K.C.Krishnamachari, a senior police officer in the Madras Presidency, was a resident of Tirupati Town and belonged to a traditional Sri Vaishnavite family. He was very dear to his mother Kuppacchi, as he was the only surviving male child born to her. He had two sisters Rajamma and Sulochana. The family tradition is very ancient and has its origin in Sriman Nallan Chakravarthy, a contemporary and a close disciple of Sri Bhashyakar Srimad Ramanuja of 11th Century A.D. His great grand father's grandfather came from a village called Karumbur, a village near Kanchi of Lord Varada.
He was known for his belief in God and innocence from his childhood. His grand father in order to pacify him due to various childish ways used to tell him to go out into open yard in the house and face the sky with closed eyes and open mouth, promising him that God would drop candy into his mouth. He it is said would do so standing for quite long time before he was rewarded (by the grand father) and the young believer used to jump with joy for having been rewarded by God. He was a pet for all in the family as he was the only son. He had two sisters. As the joint family system was still in vogue his cousins also lived with him. He was very intimate with his cousin Sri Ramanujam. In fact Dr.Varadachari was called Chinna samy and Ramanujam, Dorai samy as he was elder to him. This cousin had enormous influence on the prospective Seer. It is said that Sri Ramanujam who participated in the Scout movement in the early 1900, had on one occasion given his skin for graft for a young victim of fire accident for which the King offered the honor of King Scout. The little Boy refused the honor stating that he gave his skin for his brother and not for any honor or reward from the King least of all from a foreign ruler. The same cousin was a pioneer in spreading the Ragi Malt culture and home made table salt apart from many other products of beauty and has strived throughout his life to be a self supporting person. His products Ovomalt and Yto malt health drinks, are the first ones using Ragi released in the market.
He had his school education in the then Mahant Hindu High School, Tirupati, up to the Matriculation Standard. He did his F.A. (Maths, Physics, Chemistry) from the Christian College, Madras in 1921. His personality and the principles he was observing were such, that every one in the hostel from the watchman to the cook had paid special attention to him. The cook used to send his food specially made without onions and other items that a Srivaishnavite would not consume, to his room with also a glass of milk in the night. His colleagues in the college used to call him caveat cat and were envious of him though they never grumbled such special service to him.
Instead of continuing his education he participated in the Non-Cooperation movement from 1921 to 1923. During this period he developed interest in religion and Philosophy and started reading Swami Vivekananda and Sri Aurobindo. The works of Swami Vivekananda read in depth in 1920's, created in him deep change in life on 22nd Feb 1921, as he recorded in his diary. He started practicing Raja Yoga with a predominant stress on Gayatri japa and meditation even as advocated in the Sri Vaishnavite tradition. In 1923 he joined B.A(Hons) Philosophy in Madras Christian College. He had consistently a distinguished educational career and had he not opted for B.A(Hons) Philosophy which in those days was considered a prestigious course to study, he would have been an Agricultural Scientist as he got admission for B.A(Agri) also. He was a gold medallist of the Madras University in his B.A(Hons) in 1926. He was much influenced by one of his professors Mr. Hogg who helped him in understanding the theories of evolutionism and subjective Idealism.
He was a person with above average height, very fair complexioned with well-proportioned limbs. He had a very melodious resonating voice that was capable of putting the audience into rapt attention. His eyes were sharp and when he looked at others compassion used to overflow from them. From 1945 onwards he wore dhoti with a long coat and used to wear a white turban.
He got married in 1926 to Sow. Rukmini (Rajamma) who belonged to a distinguished family of Patrachariars. His wife's uncle was Rao Bahadur Narasimhachariar, who was District Judge in the then Madras Presidency. This marriage resulted in many good things in his life of which his contact with V.K.Narasimhan, a brother-in-law is one. Sri V.K.Narasimhan was a student of B.A(Hons) Economics those days but had been active in the Freedom Movement of India. Sri V.K.Narasimhan belonged to the group of patriots who wanted Freedom from the foreign rule quickly even if it were to be through violent means. He was able to influence Dr. Varadachari much in such thinking. Bhagat Singh and his ways attracted these young persons and it is believed they participated in several cases of breaking the laws of the land. As his father was a senior Police Officer in the Government of Madras Presidency and the uncle of his wife was a District Judge, this put the family in awkward position. He was however weaned away from active participation in the freedom movement by his father and the uncle of his wife and he was persuaded to continue his education. However, he continued the acts of burning foreign articles and clothes and used to participate very actively in the Khadi movement and was a total Gandhian for a long time to come. He used to spin the charka and make his own paper through hand processing. Till the last day of his life he never wasted paper and used the reverse of the wedding/invitation cards and most of the notes he has taken from the various books he read were recorded by him on these cards only.