John Mazzilli was born in London, Ontario to Italian immigrant parents. He attended St. Bernadette and Notre Dame Elementary School and graduated from Catholic Central High School. He began his business career at the age of 15 when he obtained several landscaping contracts for commercial developments during the summer months.
After attending the University of Western Ontario, John joined a major real estate company, where he earned the prestigious Platinum Award for Excellence in Sales. He is presently self-employed managing several residential and commercial properties in London.
John managed a successful campaign for his brother, Frank Mazzilli, who represented the riding of London-Fanshawe for the Ontario Progressive Conservative Party from 1999 – 2003. In 2002, John decided to pursue his interest in public service by joining the office of the Chair of Management Board and Minister of Culture at Queen’s Park.
John ran unsuccessfully for the Conservative Party of Canada in the Canadian Federal Election, 2004 in the riding of London-Fanshawe. John ran as the Conservative candidate in London North Centre for the 2006 Federal General Election, where he finished second behind incumbent Liberal MP Joe Fontana.