Martin Ritchie Sharp (21 January 1942 – 1 December 2013) was an Australian artist, underground cartoonist, songwriter and film-maker.Sharp made contributions to Australian and international culture from the early 1960s, and was called Australia's foremost pop artist. His psychedelic posters of Bob Dylan, Donovan and others, rank as classics of the genre, and his covers, cartoons and illustrations were a central feature of Oz magazine, both in Australia and in London.