Narayan Sanyal was born in Calcutta to Chittasukh Sanyal and Basantalata Devi. His family consisted of wife Sabita Sanyal; elder daughter Anindita Basu, son in law Amitabha Basu; son Tirtharenu Sanyal, daughter in law Sharmila Sanyal; younger daughter Mou Sanyal Talukdar, son in law Soumitra Talukdar.
Although Sanyal is known mostly as a novelist, he was also an eminent civil engineer by profession. After graduating in science from the University of Calcutta, he passed Bachelor of Engineering from Bengal Engineering College in 1948. Thereafter he joined Public Works Department and later National Buildings Organisation, Ministry of Works and Housing, Eastern Region, Govt of India. He was a Fellow of the Institution of Engineers (India) and a Fellow of the Association of Engineers (India). He also wrote books in Civil Engineering such as Vaastu Vigyan.
A biography of Narayan Sanyal was written by Pradip Dutta – Ami Narayan Sanyal Ke Dekhechi.