Worldwide sales of the Christchurch singer's debut album Pure yesterday broke the one million mark.
Westenra last night admitted the news was yet to sink in.
"It's like, wow. Overwhelming.
"Thinking over one million people have bought my album is just amazing. A little girl from Christchurch and look what has happened. It's a massive compliment."
Westenra has been back in New Zealand three weeks after a five-month stint in Britain promoting the album.
While there she sang for the Queen three times and also performed in front of United States President George W Bush and British Prime Minister Tony Blair.