Desmond Robert "Bill" Leak (9 January 1956 – 10 March 2017) was an Australian editorial cartoonist, caricaturist and portraitist.

Raised in Condobolin and Beacon Hill, Sydney, Leak attended Julian Ashton Art School during the 1970s. His cartoons were first published in 1983 in The Bulletin and after he drew for The Sydney Morning Herald until 1994, when he was recruited by News Limited to contribute to The Daily Telegraph-Mirror and later to The Australian. As an artist and illustrator, Leak was acclaimed by journalist Peter FitzSimons as "colossally talented, driven, and passionate for his craft".

Leak entered paintings into the Archibald on several occasions, having won the People's Choice Award in 1994 for his portrait of Malcolm Turnbull and the Packing Room Prize twice, in 1997 and 2000 for his portraits of Tex Perkins and Sir Les Patterson respectively. Leak's novel Heart Cancer was published in 2005 and in 2008 ABC TV aired his six-part series Face Painting.

Leak's editorial cartoons for The Australian were at the centre of several controversies. Works that received considerable media coverage include a 2006 cartoon drawn during the West Papuan refugee dispute, a series of cartoons in 2007 that featured Kevin Rudd as Tintin, a 2015 cartoon depicting starving Indian people attempting to eat solar panels and two cartoons in 2016, one an illustration of a neglectful Aboriginal father and another that depicted same-sex marriage campaigners wearing rainbow-coloured Nazi uniforms.