Nandana Sen (19 August, 1967), is an Indian actress, screenwriter, children's author and child-rights activist.
Her first film role in Bollywood was Sanjay Leela Bhansali's Black (2005) starring Rani Mukherjee and Amitabh Bachchan, in which she played the role of Rani's 17-year-old younger sister.
After teaming up on a succession of projects with Indian directors including Ram Gopal Varma and Ketan Mehta, Sen signed for one of the principal roles in the jarring, terrorist-themed American drama The War Within (2005) which premiered at the Toronto International Film Festival and, in the process, began to cultivate a reputation for being drawn to offbeat, challenging and demanding roles, often with a social or political theme.