Basu was born in Delhi to a Bengali Hindu family. She is the second of three sisters, the elder one being Bidisha and the younger one, Bijayeta. She lived in Delhi till the age of eight in Pampoosh Enclave, Nehru Place and studied at Apeejay High School. Her family then moved to Kolkata where she studied science till 12th standard at Bhavan's Gangabux Kanoria Vidyamandir. Basu, who describes herself as a tomboy, was pampered as a kid and was very naughty. She was fondly called 'Lady Don' in her school as everyone was scared of her and she was short and round.
