She is best known for her role as Dolly Tan on the English-language popular and award-winning Singaporean local sitcom Under One Roof.
[2] From 1995 to 2003, she portrayed Dolly Tan on the English-language popular and award-winning Singaporean local sitcom Under One Roof.
In June 2014, she performed with the theatre company Generasia in Women of Asia, a live production at LASALLE College of the Arts.
[4][3] In early 2018, it was announced that Koh would be joining the cast of Toggle's original series Dance With Me.
[5] She was cast as Neena Goh in the 2018 American romantic comedy-drama film Crazy Rich Asians, based on the novel of the same name by Kevin Kwan.