Padraic 'Paddy' McGuinness was educated in Sydney Catholic schools and received a BEc from Sydney University and an MSc from the London School of Economics. In the 1950s and 1960s he was associated with the libertarian, anti-establishment movement, the Sydney Push.

After completing his MSc, McGuinness worked as an economist in England and France and lectured at the University of London (1969-1971). While at the University of London he also edited the International Currency Review. After a brief period as adviser to the federal government during the mid-1970s, he worked as a reviewer and columnist for publications such as the National Times. This was followed by several years at the Australian Financial Review as editor, columnist and foreign correspondent (1982-1989). He was, subsequently, a visiting fellow at the Australian Graduate School of Economics (1988-1991) and a columnist for the Australian (1989-1994).

From 1994 McGuinness was a regular columnist for the Sydney Morning Herald where he continued to argue against left-wing ideologies, a contrast to his Marxist views of the 1950s and 1960s. In 1997 he was appointed editor of the conservative quarterly Quadrant and continued in that position until the end of 2007.