Markham /ˈmɑrkəm/ , a city in the Regional Municipality of York, lies within the Greater Toronto Area of Southern Ontario, Canada. At the 2011 Canadian census it had a population of 301,709. Markham's population in 2015 was estimated at 342,000 through The Region of York population census data monitoring. The city is the fourth-largest community within the Greater Toronto Area after Toronto, Mississauga and Brampton. Markham changed its status from town to city on July 1, 2012.