Hayley Dee Westenra (born 10 April 1987) is a New Zealand singer, Classical crossover artist, songwriter and UNICEF Ambassador. Her first internationally released album, Pure, reached No. 1 on the UK classical charts in 2003 and has sold more than two million copies worldwide. Pure is the fastest-selling international début classical album to date, having made Westenra an international star at age 16. In August 2006, she joined the Irish group Celtic Woman, was featured on their Celtic Woman: A New Journey CD and DVD, toured with them on their 2007 Spring Tour, and was also featured on their DVD, The Greatest Journey: Essential Collection, released in 2008.

Across classical music to easy listening, folk and pop style songs, Westenra has performed songs in English, Irish, Welsh, Italian, German, French, Portuguese, Latin, Japanese, Mandarin Chinese, and Māori.