Sunny was born in Ontario, Canada to parents who emigrated from India. Her real name is Karenjit Kaur Vohra. She was good at sports during her school days. In 1996, her family moved to California. It was a difficult adjustment for the little Canadian girl. She started her career as a model for Penthouse, Hustler and High Society. She was Penthouse Pet of the Year for 2003. She was named by Maxim as one of the 12 top porn stars in 2010.
In 2005, she signed a three-year contract with Vivid Entertainment, with which she transitioned into the world of hardcore porn. She did only lesbian scenes during her contract. In 2007 she re-signed with Vivid Entertaiment and agreed to perform for the first time with men on camera, but exclusively with her fiance, Matt Erikson. She became a known porn star with her fan base having from all over the world.
In 2008 she revealed that she was no longer exclusive to Matt Erikson. She worked for different studios (Brazzers, Naughty America, Twistys), where she worked with male talent like James Deen or Charles Dera. She was nominated for 3 AVN Awards (Best All Girls Group Sex Scene and Web Starlet of the Year in 2010 and Crossover Star of the Year in 2013). She was also nominated for two XBIZ Awards (Web Babe of the Year in 2008 and Pornstar Site of the Year in 2012). In 2013, she announced her retirement from the adult industry.
Since 2009 she has also produced and directed her own films. She produced and directed over 60 films under her production company, Sun Lust Pictures. She also cooperates with fitness magazines. In 2005, she moderated Indian MTV Awards. She is very popular in India (she is often called "Indian Marilyn Monroe"). In 2011, she participated in the Indian reality television series Big Boss. In 2012 she made her Bollywood debut in Pooja Bhatt's erotic thriller Jism 2. She is the first Indian porn star to make it into Bollywood films. As of 2016 she has appeared in over 20 Indian films.
She was engaged to Matt Erikson, a vice-president of marketing at Playboy Enterprises but they broke up in 2008. Since 2011, she has been married to Daniel Weber. He is an actor, Guitarist and Business Manager. In July 2017 they adopted their first child.