Rimi Sen's birth name is Shoumitra Sen. In an interview she said she doesn't use her original name because it sounds unusual. She moved to Mumbai to become a film actress.

Rimi was first noticed when she auditioned for a Coke advertisement. The director of the ad Priyadarshan was impressed by her & cast her in his film Hungama. The film was a hit & established her in the industry. She then played Amitabh Bachchan & Hema Malini's granddaughter in the hit film Baghban. Her next big hit was the Yashraj produced Dhoom. 

2006 was successful for her when Phir Hera Pheri & Golmaal were both box office hits. Her next release was the sequel to Dhoom titled Dhoom 2 which was a blockbuster hit. 

Rimi is now going by the screen name Rimii. She said the name change as a career move there are many other Sens working in Bollywood right now & a single name may help her stand out from the crowd and stay apart from others.