Sabine Singh is a first-generation American, born in Suffern, New York. Before graduating from NYU's Tisch School of the Arts, Singh attended The University of Michigan, as well as the London Academy of Music and Dramatic Arts (LAMDA) and the British American Drama Academy both in London. Continuing her love of Shakespeare, Singh also studied at Balliol College at the University of Oxford.
Singh was a founding company member of Jim Simpson's and Mac Wellman's award winning The Flea Theater. Sabine was one of the first "BATS', the Obie Award winning resident acting troupe of The Flea, that primarily presented new and experimental voices of the downtown NY theatre world. Sabine recently appeared off-Broadway as "Olivia" in the critically acclaimed production of The Gold Standard, a play by Daniel Roberts. From The New York Times review: "Olivia (Sabine Singh) is a genuine beauty who spends Act 1 ... imitating Michelle Pfeiffer's sinuous lounge singer from The Fabulous Baker Boys... She's the kind of stunning blonde who practically stops traffic."
Her film credits include Tony Goldwyn's Someone Like You, The Anarchist Cookbook, Ricky Six and the award winning The Fine Line Between Cute and Creepy. Singh's film Maryam opened Robert De Niro's first Tribeca Film Festival, where Sabine was honored and invited to participate as guest speaker. TV credits include guest and recurring roles on The Sopranos, Las Vegas, Dawson's Creek, Charmed, CSI: NY all the Law & Orders as well as Unscripted for George Clooney, Section Eight and HBO. After meeting Singh, Stephen Colbert and Paul Dinello specifically created the role of 'Yasmine Sarong' for the Comedy Central hit show Strangers With Candy.
Beginning March 2007, Singh filmed more than 170 episodes as Greenlee Smythe on All My Children, replacing the original Greenlee Rebecca Budig who had left the show two years prior. Singh's performance prenominated her as Best Supporting Actress for the Daytime Emmy Awards as well as Daytime Confidential's 2007 'Top New Comer' award. In December 2007, it was announced that Singh was fired from the role, to be replaced by Budig. The producers of AMC broke Singh's contract in order to bring back the original actress. This sparked a firestorm of controversy because of how Singh was treated and let go. Besides giving Singh a four-day notice of termination, her firing no longer qualified her for the Emmy. Fans were appalled by the commercials that ABC put out calling Budig the "Real" Greenlee, as well as the clock counting the days until Rebecca's return, which watermarked the screen during Singh's final month of airing. Singh last aired on All My Children on January 15, 2008. Budig returned the next day.
After her exit from All My Children, Singh returned to theatre work and appeared in the one woman play The Euthanasiast — Liza Lentini's exploration of care-givers and the right to die — at PS 122 in New York City. The Euthanasiast opened May 31, 2008 and played for a limited engagement.
Singh spent the rest of 2008 and 2009 traveling the world, hosting a TV travel documentary for the Voyages Channel.  She also signed on as the face of Bacardi's Bombay Sapphire Gin, continuing to travel, and film episodes acting as a spokesperson for the brand. 
She returned to NY to play Amy Townsend in Law & Order: Criminal Intent.
Singh is primarily based in New York City. She is the sister of artist Schandra Singh.
Singh is an active member of The Art of Living, a global non-profit education and service organization.
In early 2012, Singh was diagnosed with breast cancer. As of late 2014, her cancer was in remission.