In 1999, the former Townships of Guelph, Eramosa and part of Pilkington and Nichol were amalgamated and formed the Township of Guelph/Eramosa. Guelph/Eramosa was incorporated on January 1, 1999.
Eramosa Township was established in 1784, although at this time it was not surveyed when the Mississaugas surrendered the land to the government. Eramosa Township was first surveyed in 1818 by Samuel Ryckman. This was the first time the name Eramosa had been used to describe the parcel of land.
John Harris, the first settler of Eramosa Township built a small shanty in 1821 followed by Col. Henry Strange in 1840. In the 1850’s the community, originally known as Brotherstown, became known as Rockwood.
In 1825, Samuel Rife was the first settler of Guelph Township. In 1827, a group of Scottish settlers called the La Guayrans, who originally settled in Venezuela, were resettled in Guelph Township by the Canada Company.
Throughout the 19th and 20th centuries Guelph Township became a centre for agricultural excellence through rural and agricultural educational institutions.