Leong was born in Bahau, Negeri Sembilan, Malaysia. R&B singer Z-Chen is her older cousin. She debuted her singing career in Taiwan and signed to Rock Records in October 1997. She then adopted the English name “Fish”, because the last character of her Chinese name “茹” sounds the same as “魚” (fish) in Cantonese. She was discovered by Jonathan Lee, who later also became her godfather, as she received Mandarin training upon arriving in Taiwan as her mother tongue is Cantonese. Her debut album, Grown Up Overnight, was released in September 1999, but had many promotions cancelled due to 921 earthquake. Her singing career managed to take off after the release of her second album, Courage (2000).

In February 2010, Leong married Taiwanese wine merchant Tony Chao in Boracay, Philippines, and their child Anderson Chao was born in April 2014. On September 8, 2019, Leong announced their divorce at a press conference for her new album in Taipei. She declined further comments on alleged cheating by Chao.