The Western Fair is a fair held annually in London, Ontario, Canada in early September.

The first Western Fair was held in September 1868 in downtown London, northeast of the current location of Victoria Park. Organizers had hoped to use the Crystal Palace Barracks as the main exhibition area. Livestock shows took place on the parade grounds outside the Crystal Palace.

In 1887, when the fair gained legal status through the Provincial Charter and Act of Incorporation, it moved to 900 King Street in east London, where the fairgrounds remain today. The present fairgrounds were purchased for $65,000. Except for an eight-year period between 1939 and 1947 when the Canadian Department of National Defence occupied the grounds and 2020–2021, the Western Fair has operated on the new site.

John Huse Saunders was President of the Western Fair Association (WFA) for 22 years.^[when?] He devoted more than 50 years to the Western Fair and was known throughout North America as a poultry breeder. After receiving Honorary Presidential status the WFA changed the by-laws and limited the term to three years.

In 2011, the former Western Fair Association re-branded itself as the Western Fair District, to better represent the reality that the grounds and building facilities had expanded beyond a 9-day fair to year-round activities.

With 2020 & 2021's cancellation due to the COVID-19 pandemic, the 145th was deferred to 2021.

As of 2025, the rides are;

The Western Fair runs during the second full week of September, starting on Friday and ending on Sunday.