The first Western Fair was held in September 1868 in downtown London, northeast of the current location of Victoria Park.

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.

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.

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

The original basis for the Western Fair was agricultural displays, arts and crafts, and vendors, with a heavy emphasis on competition.

A slot machine facility on the site was opened to the public on September 28, 1999, as authorised by the Ontario Lottery and Gaming Corporation.

[5][6] The Western Fair Museum and Archives began with the efforts of Inge Sanmyia, who was working on her PhD in history at Wilfrid Laurier University in Waterloo, Ontario in 1997.