Narendranath Dutta was born in Shimla Pally, Kolkata, West Bengal, India on 12 January 1863 as the son of Viswanath Dutta and Bhuvaneswari Devi. Even as he was young, he showed a precocious mind and keen memory. He practiced meditation from a very early age. While at school, he was good at studies, as well as games of various kinds. He organised an amateur theatrical company and a gymnasium and took lessons in fencing, wrestling, rowing and other sports. He also studied instrumental and vocal music. He was a leader among his group of friends. Even when he was young, he questioned the validity of superstitious customs and discrimination based on caste and religion.
In 1879, Narendra entered the Presidency College, Calcutta for higher studies. After one year, he joined the Scottish Church College, Calcutta and studied philosophy. During the course, he studied western logic, western philosophy and history of European nations.
There started to arise questions about God and the presence of God in young Narendra's mind. This made him associate with the Brahmo Samaj, an important religious movement of the time, led by Keshab Chandra Sen. But the Samaj's congregational prayers and devotional songs could not satisfy Narendra's zeal to realise God. He would ask leaders of Brahma Samaj whether they have seen God. He never got a satisfying answer. It was during this time that Professor Hastie of Scottish Church College told him about Sri Ramakrishna of Dakshineswar.