[1] On television, Koh is well known for her role as the ambitious lawyer Angela Ang on the MediaCorp Channel 5 legal drama The Pupil.

Theatre Award Best Actress nomination in 2008 for her role in Ovidia Yu's acclaimed play Hitting (On) Women.

Recent work include Pangdemonium's Swimming with Sharks, Alfian Sa'at's sold-out play Cooling Off Day by W!LD RICE, Tan Tarn How's critically acclaimed Fear of Writing,《我爱阿爱》 by The Theatre Practice, Poop by The Finger Players, which was also nominated for the Life!

[2] Koh made her international acting debut in the rom-com Crazy Rich Asians, directed by Jon M. Chu, starring Constance Wu and Henry Golding, and based on the critically-acclaimed novel of the same title by Kevin Kwan.

Koh is known for her support of the Singaporean arts scene,[5] and her desire for transparency in regards to the MDA's censorship rulings.