St. Agatha is an unincorporated community in Wilmot Township in the Regional Municipality of Waterloo, Ontario, Canada.

It is recognized as a designated place by Statistics Canada.

The village was settled by Amish Mennonites from Pennsylvania and Alsace-Lorraine in 1824.

In the 1830's Lutherans and Roman Catholics began settling in the area, either buying land from the Amish Mennonites or from the Crown.

[2] In 1865, Father Eugene Funcken and his brother Father Louis Funcken established St. Jerome's College in the village.