Guelph ( (listen) GWELF; 2021 Canadian Census population 143,740) is a city in Southwestern Ontario, Canada. Known as The Royal City, it is roughly 22 km (14 mi) east of Kitchener and 70 km (43 mi) west of Downtown Toronto, at the intersection of Highway 6, Highway 7 and Wellington County Road 124. It is the seat of Wellington County, but is politically independent of it.

Guelph began as a settlement in the 1820s, established by Scotsman John Galt, who was in Upper Canada as the first superintendent of the Canada Company. He based the headquarters, and his home, in the community. The area—much of which became Wellington County—was part of the Halton Block, a Crown Reserve for the Six Nations Iroquois. Galt is generally considered Guelph's founder.

For many years, Guelph ranked at or near the bottom of Canada's crime severity list. However, the 2017 index showed a 15% increase from 2016. It had one of the country's lowest unemployment rates throughout the Great Recession. In late 2018, the Guelph Eramosa and Puslinch entity had an unemployment rate of 2.3%, which decreased to 1.9% by January 2019, the lowest of all Canadian cities. (The national rate at the time was 5.8%.) Much of this was attributed to its numerous manufacturing facilities, including Linamar.