Rajnarayan Basu (Bengali: রাজনারায়ণ বসু; 1826–1899) was an Indian writer and intellectual of the Bengal Renaissance. He was born in Boral in 24 Parganas and studied at the Hare School and Hindu College, in Kolkata, Bengal. A monotheist at heart, Rajnarayan Basu converted to Brahmoism at the age of twenty. After retiring, he was given the honorary title of Rishi or sage. As a writer, he was one of the best known prose writers in Bengali in the nineteenth century, writing often for the Tattwabodhini Patrika, a premier Brahmo journal. Due to his defence of Brahmoism, he was given the title "Grandfather of Indian Nationalism".