Karen Joy Morris, or Karen Mok Man-Wai, or Mò Wénwèi(莫文蔚, born in June 2, 1970, Hong Kong) is a Hong Kong-based actress and singer. She is known for her versatile and expressive voice, which can be at times husky, low and sensual or quirky and childlike in ballads to other times wild and powerful in more rocky songs.

She is 1/2 Chinese, 1/4 Welsh (paternal grandfather), 1/8 Iranian and 1/8 German. Mok attended Diocesan Girls' School, Hong Kong (from primary to secondary), majored in Italian literature when studying in the University of London and United World College in Trieste, Italy. She is the sister of the writer and producer Trevor Morris and the descendant of Alfred Morris, the first principal of King's College, Hong Kong. Mok speaks English, Cantonese, Mandarin, Italian, French.

Mok is often credited as Karen Mok in Chinese movies, but as Karen Joy Morris (her birth name) in Hollywood movies. She supplied the voice of Princess Kida for the Cantonese dub of Disney's Atlantis (2001). Mok performed in the international tour of the hit Broadway musical "RENT" as Mimi during the Hong Kong stops in December 2005.