The Regional Municipality of York, also called York Region, is a regional municipality in south-central Ontario, Canada, between Lake Simcoe and Toronto. It replaced the old York County in 1971. In 2006, nearly 893,000 people were living in the Regional Municipality of York. It is the fastest growing region in Canada and it is expected to grow to more than 1.5 million people by 2031. The whole region is part of the Greater Toronto Area and is part of the Golden Horseshoe. The capital of the region is in Newmarket.