Knox trains as an architect at Edinburgh College of Art in Scotland from 1963 to 1967 and Heriot-Watt University in Edinburgh from 1967 to 1968, and works as an architect before establishing himself as a cartoonist. He works in animation from 1970 to 1975 for Halas & Batchelor in London, Potterton Productions in Montreal, and Kotopoulis Productions in Toronto. He then joins Red Weekly and Socialist Challenge as a political cartoonist, as well as contributing to various children’s comics for IPC Media from 1975 to 1988.
Knox signs much of his political work “Blotski,” and he and Republican News cartoonist Brian Moore, better known as “Cormac,” work together as “Kormski,” drawing the anti-clerical strip “Dog Collars” for Fortnight magazine. Since 1989 he has been the editorial cartoonist for The Irish News, a nationalist newspaper based in Belfast. Since 1996 he has contributed the “As I See It” feature to Hearts and Minds on BBC2 Northern Ireland. From 1997 to 1998 he is political cartoonist for Ireland on Sunday.