Originally, she worked as an investment bank analyst in New York City and Hong Kong before starting her acting career.

For TV and film, Montano has appeared on Close to Home, Days of Our Lives, Nashville, Scandal, The Young and the Restless, This Is Us and Veep.

As a voice actress, she has provided the voices of Pudding in Space Channel 5 and its sequel, Arcee on Transformers: Prime, Cali in the Skylanders series, Katana on Beware the Batman, the President in Saints Row IV, the female Inquisitor in Dragon Age: Inquisition and Yuna in Ghost of Tsushima.

She is talented in using many different accents, including Chinese, Filipino, British, Southern, Thai, Vietnamese, Eastern European and Japanese.

[7] In 2021, Sumalee Montano gained acclaim for her role as Inoue Sato in the Peacock TV series The Lost Symbol.