While records of the earliest fairs were destroyed by fire, history sources indicate it began as a one-day cattle show in mid-January and was called the Centre Wellington Fair.

By 1870, the event transitioned to become a two-day fair in September and was referred to as the Union Exhibition of the Centre Wellington and Nichol Agricultural Societies. In addition to livestock, exhibitors also entered friendly competitions in grain, roots, fruit dairy produce, domestic manufactures and ladies’ work.

Entertainment was added to the fair by the early 1900s. In 1912, the fair featured musical entertainment, horse racing and roadster speeding.

While it was advertised as the Fergus Fall Fair in the 1920s, the event was known as the Centre Wellington Union Fair in the 1930s, the Fergus Fall Fair in the 1940s and the Wellington County Fair through the 1950s and 1960s. 

In 1937, gates marking the entrance to the fairgrounds at Victoria Park were presented by the Department of Agriculture in recognition of 100 years of service. 

After 1965, the Fergus Fall Fair name was used consistently.

The first Queen of the Fair or Miss. Fergus Fall Fair competition was held in 1979 and won by Mary Wallace. The competition was opened to males and changed from Queen to Ambassador in the 1990s.  

Truck and tractor pulls were added to the fair in the late 1970s and have remained crowd favourite events ever since. 

A big move took place in 1997 when the fair outgrew Victoria Park and transitioned to its current location at the Centre Wellington Community Sportsplex.

Jeanine Wallace was the first and only Fergus Fall Fair Ambassador to win the title of CNE Ambassador of the Fairs. She earned the provincial title in 2004.