Sunil Gangopadhyay was born in 1934 in Faridpur in what is now Bangladesh. He studied at Surendranath College, Dumdum Motizhil College, City College, all affiliated with the University of Calcutta and thereafter obtained his Master's degree in Bengali in 1954.

Gangopadhyay was the founder editor of Krittibas , a seminal poetry magazine which began publishing in 1953 and rapidly became a platform for a new generation of poets experimenting with new poetic forms and themes. Later, he began writing for various publications of the Ananda Bazar group, a major publishing house in Kolkata, something he continues to do to this day. In 2008, after serving five years as its Vice President, he was elected the President of the prestigious Sahitya Akademi, India 's national academy of letters.

Author of well over 200 books, Gangopadhyay is an astonishingly prolific writer who has excelled in different genres though he declares poetry to be his first love. His Nikhilesh and Neera series of poems (some of which have been translated as For You, Neera and Murmur in the Woods) have proved extremely popular.

Gangopadhyay is known for his unique style of prose. Arjun, Pratidwandi , filmed by legendary director Satyajit Ray (as The Adversary), Aranyer Din-Raatri (also filmed by Ray as The Days and Nights of the Forest) and Ekaa ebong Koyekjon are some of his most well-known works of fiction. His historical fiction Sei Somoy , translated into English by Aruna Chakravorty as Those Days , received the Indian Sahitya Akademi award in 1985. Sei Somoy continues to be a best seller more than a decade after its first publication. The same is true of Pratham Alo (also translated recently by Chakravorty as First Light), another best selling historical fiction.

Gangopadhyay has written, and still writes, in many other genres including travelogues, children's fiction, short stories, features and essays.