Sunil Das was born in Kolkata. He joined the Government College of Art & Craft, Kolkata, in 1955 and later won a French Government Scholarship to study at the École des Beaux-Arts in Paris. A founder member of the Society of Contemporary Artists in Calcutta, Sunil Das was known for energetic charcoal drawings of horses and the bullfights observed in Spain.
He joined Government service for the Ministry of Textiles and since then continued art and official work simultaneously holding key positions like Member of Purchase Committee for National Art Exhibition of 1979, and Miniature Format Exhibition 0f 1980, Jury for Hyderabad State Akademi, Committee member of 5th Triennale India in 1982 as also a member of the General Council of the Lalit Kala Akademi, New Delhi.