Fiona Fung (Traditional Chinese 馮曦妤; Simplified Chinese 冯曦妤; born December 14, 1983), also known as Fung Hei-yu, is a Cantopop singer-lyricist based in Hong Kong.At the age of 16, Fung was introduced by friends to Hong Kong composer Chan Kwong-wing. She then started her career working back stage in Chan's workshop. In the year 2000, she joined Chan's newly founded studio, Click Music. Since then, Fung produced more than 200 pieces of advertisement music. She also worked as a backing singer and demo singer for various artists, and as a vocal producer for movies including the Infernal Affairs trilogy, Initial D, Daisy, The Warlords, and several DreamWorks animations.