Toni Onley OC (November 20, 1928 – February 29, 2004) was a Manx painter noted for his landscapes and abstract works. Born in Douglas on the Isle of Man, he moved to Canada in 1948, and lived in Brantford, Ontario.
Among his works are many watercolours depicting the northern Canadian landscape. Onley painted natural subjects according to his view to create beautiful landscapes in the Canadian tradition. Icebergs, trees, water and coasts are the prominent features in these artworks. He also painted abstractly, particularly during the 1960s, when he produced his Polar series.
He was made an Officer of the Order of Canada in 1999. He was made a member of the Royal Canadian Academy of Arts. He died at the age of 76 in a plane crash on the Fraser River near Maple Ridge, British Columbia, as he was practising takeoffs and landings in a Lake LA-4-200 Buccaneer amphibious plane.