A haunting portrait of the late actor Heath Ledger has taken out the people's choice award at the Archibald Prize exhibition.

The painting "Heath", by Vincent Fantauzzo, was announced as the winner of the popular prize at the Art Gallery of NSW on Thursday.

More than 32,000 people voted in the competition.

The portrait, which features three images of Ledger, was painted just weeks before the late actor's death in New York in January.

The Art Gallery of NSW said the popularity of the painting had helped the gallery record its biggest attendance since the competition began in 1921.

A spokeswoman said the Ledger family and Fantauzzo had decided to donate the painting to the gallery.

Melbourne-based Fantauzzo receives $2,500 and a $1,000 gift card for winning the award.

The Archibald, one of Australia's most prestigious art awards, was won this year by Sydney artist Del Kathryn Barton, with her painting You are what is most beautiful about me, a self portrait with Kell and Arella.