B. Lenin (Bhimsingh Lenin) is primarily a Tamil film editor who has also worked as a writer and film maker. Apart from Tamil movies, he has worked in Malayalam and Hindi films. His career as an assistant editor started in 1979 with Uthiripookkal by director J. Mahendran. He worked as assistant editor with his father in many films before he debuted as an independent editor. He has also worked as a lab technician and he is an experienced sound engineer. During the decades of 1980s and 1990s, he partnered with his old assistant V. T. Vijayan and worked with him in over 100 Tamil, Malayalam, Hindi, Kannada and Telugu films, including Geethanjali, Nayakan, and Anjali and Kadhalan, for which they were honoured with the National Award for best editing.

Lenin has won five National Awards till 2013 which also includes an award for best direction. In 2010, Lenin was a jury member at the 57th National Film Awards. In 2011, he was appointed the chairman of the Oscar Selection Committee of Film Federation of India. Lenin debuted as a director in 1983 with Ethanai Konam Ethanai Paarvai. After that he directed eight more films, four out of which were feature films and four were non-feature films. In 1992 he came up with a short film titled Knock Out and critically it was a huge success. Knock Out won the award for Best Short Film (Islamia Critic Awards) at Cairo International Film Festival. Knock Out also won the National Award for "Best First Non-Feature Film of a Director". The jury appreciated this film very much.

After 3 years, Lenin directed another short film titled "Kutravali" and won the National Award for best editing. He won the "Best Regional Film (Tamil)" award and "Best Direction" award in 2002 for Ooruku Nooruper. This film told about the issue of capital punishment and it was critically acclaimed. Apart from movies, Lenin has also directed some television shows, one of them being Solladi Sivasakthi. He also worked on Eli My Friend, which is an English film. Lenin was born to a popular Hindi and Tamil filmmaker A. Bhimsingh and has eight siblings. One of his brothers, B. Kannan is also a part of the film industry and is a cinematographer by profession.