Equally acclaimed for his poems and novels in both West Bengal and Bangladesh, the Sahitya Akademi winner, 78, leaves behind his wife and son who lives at Boston in the US.
Gangopadhyay was suffering from prostrate cancer for some time. The body has been kept at a city mortuary.
Born in Faridpur, which is now in Bangladesh, Gangopadhyay's family shifted to Kolkata before the 1947 partition of India. He obtained a Master's degree in Bengali from the University of Calcutta in 1954.
Having authored over 200 books over six decades since his first poem "ekti Chithi" (A letter) was published in the 1950s, Gangopadhyay created a niche for himself in the Bengali literary scene.
He touched upon almost all genres of Bengali literature - novels, children's fiction, poetry, literary criticism and essays, but poetry was closest to his heart.
In the 1950s, Gangipadhyay and some of his friends brought out a seminal poetry magazine "Krittibas", which published poems of only young writers and became a platform for young talents experimenting with various forms. Mr Gangopadhyay was the founder editor.
His first novel, "Atmaprakash" (Emergence), was published in 1965 in the prestigious magazine "Desh", and was critically acclaimed thought it triggered a controversy, with some calling it "obscene".
His poems in "Nira" series have retained their charm and appeal among the readers, particularly the youth, through the years.
He used several pen names including Nil Lohit, Sanatan Pathak and Nil Upadhyay and was known for his liberal and open-minded views.
In 1985, Gangopadhyay got the Sahitya Akademi award for his historical fiction "Sei Somoy" ("Those Days").
Among his other works are "Pratham Alo" ("First Light"), and "Purbo-Paschim", a novel on the partition and its effect depicted through the eyes of three generations of Bengalis in West Bengal, Bangladesh and elsewhere.
His thrillers of the "Kakababu" series were very popular among children and teenagers.
Some of his works were made into films by directors like Satyajit Ray.
Gangopadhyaye took over as Sahitya Akademi President in 2008, and launched a large number of projects to popularise Indian literature across the world, translate works from one Indian language to another, and increase interaction between writers in various Indian languages.
"Indian literature is one, written in many languages. Writers in the Naga and Manipuri languages should not feel isolated because of their location. We are thinking of ways to remove their sense of isolation," Gangopadhyay had said once.