Born to the ace actor Haradhan Bannerjee, Kaushik Banerjee made his acting debut opposite Mahua Roychoudhury in Dinen Gupta's Bengali romantic film Priyatama (1980). He claimed to fame for his lascivious role as Devendra in Ajoy Kar's Bishabriksha (1984) which is based on the novel of the same name by Bankim Chandra Chatterjee. Since his role as Devendra was much celebrated, he has often been typecast in salacious, negative roles in a number of Bengali films. He collaborated with Aparna Sen in Paromitar Ek Din (2000), Rituparno Ghosh in Shubho Mahurat (2003) and Chitrangada: The Crowning Wish (2012). He is married to ace actress Laboni Sarkar. Actor Susnato Banerjee is their only son.
