[1] Mok is the first female Hong Kong singer to win the Golden Melody Award, and to date has won it three times.

She has released 18 solo studio albums, starred in over 40 movies, and has over 15 million followers on leading Chinese social media site Weibo.

In 1987, she won a scholarship for the United World College of the Adriatic in Duino (Trieste, Italy) from which she graduated in 1989 with the International Baccalaureate.

She decided to put her theatre aspirations on hold, headed back to Hong Kong and released in 1993 her first Cantonese album Karen.

[10] Her 2021 single "Empty World" had over 3bn streams on Chinese music platforms and became an anthem during the Covid pandemic in mainland China.

[22] The Regardez Tour (2015–2016) started in Taipei and led Mok to 27 cities in Asia, North America, Europe, Australia, and New Zealand.

[31] The European leg of the tour brought her in London to the Palladium and in Paris to the Folies Bergère, making her the first Chinese pop singer to perform in this venue.

Interrupted by the events around the global Covid pandemic, the tour finished with three concerts in Hong Kong in June 2021.

Outside Greater China, she acted in the 2004 Hollywood production Around the World in 80 Days with Jackie Chan (credited as Karen Joy Morris, her birth name) and in the Thai horror movie The Coffin.

In 2001, she supplied the voice of Princess Kida for the Cantonese dub of Walt Disney's Atlantis: The Lost Empire.

In 2020, Mok sang the theme song of the Hong Kong TVB drama Flying Tiger II.

The theme song, "呼吸有害, Breathing Is Hazardous",[42] topped all radio, TV and digital platforms in Hong Kong, a first in Cantopop.

[51] In the following year, she initiated a crossover collection with Replay,[52] leading up to a launch event and pop-up store at Harvey Nichols in London in 2018.

[72] In 2017, Mok created the Morris Charity Initiative, providing support in animal welfare, education and the environment.