Seth attended Ashok Academy and graduated from St. Xavier's College, Mumbai with a degree in Economics and Commerce. She is married to film director Danish Aslam. and together they have a daughter named Alina.

A controversy arose when Seth commented on Twitter in critique of Indian Prime Minister Modi's #selfiewithdaughter campaign for women and girls, which he announced in his Mann Ki Baat radio address. After this she started to receive abuse through Twitter and social media. This resulted in members of the media and Bollywood defending her against the abuse.^[8]

Seth started her career as a guest relation executive at the Taj Mahal Hotel, Bombay. According to her, her entry into the world of modeling happened by chance. A 'couple of people' had asked her if she’d like to model and, at that time, it just 'meant extra pocket money'. Over the span of her career as a model she did several commercials including Clean and Clear moisturiser, TATA Home Finance, Ponds Talc, Frooti, Lifebuoy Soap, ICICI Prudential Life Insurance, LG, Airtel, Mrs. Marino Hair Softener, Stayfree Secure, Dominos etc.

Eventually, she moved to television. At the start of her career in modeling and television, Seth said that "fate was pushing me in that direction and I just followed the course." She also said that it was her stint on Channel V "that firmly put me on the map."^[9]

For Channel V, India she hosted First day First show and Junglee Jukebox. She acted in many serials such as Kyun Hota Hai Pyarrr, Des Mein Niklla Hoga Chand and Shararat with actress Farida Jalal and Eva Grover. She played the role of a fairy who receives magical powers at the age of 18. Seths's performance received critical acclaim and the show proved to be a hit. She is also seen in Rishta.com on Sony Entertainment Television. On Rishta.com, she said in an interview that, "They (the Yash Raj serials) haven’t got any TRPs at all. But it’s not for the people who are watching TV in the first place. The whole TRP game is very skewed. I don’t believe that in a population of over a billion people, 15,000 households decide what the entire country wants to watch. This lot of Yash Raj was conceptualised for those who are not watching TV". She further said in the same interview that "All our loyal audience for my serial on TV is in London, America, South Africa, Australia. It’s not that the Indians will not like it, it’s just sad that they are not aware of it, because the publicity has been disappointing. She has also hosted several seasons of Comedy Circus on Sony Channel."^[9]

She has starred in a few films. On moving from television to films, she stated that, "I haven’t really moved on to anything. It’s not that I would not do TV and only do films. Yes, more avenues have started opening for me. I am game for doing something exciting on any medium – stage, celluloid or TV".^[9] She is probably best known for her role as Fatima "Fatty" in Fanaa (2006) with Aamir Khan and Kajol. She starred in Tara Rum Pum, produced by Yash Raj Films and made an appearance in Prakash Jha's film Raajneeti in 2010. On her role in Rajneeti, she said in an interview that "I am hoping that my hard-hitting role in Rajneeti will change my being typecast, because it is the most unlikely character one would expect me to play".^[9]

Television