Municipal Heritage Designation (Part IV)
Hyde Mill Ruins
City of Mississauga, Ontario
Also known as Stone Foundations of Hyde's Mill, Ontario Mills, 69 Church Street

Featured are the walls of squared rubble and staggered brick.
Photo: Paul Dubniak, 2008.
- Built
- 1840
- Recognized
- 1992
- By
- Local government
The register’s text, word for word
Description
The Hyde Mill Ruins are located at 0 Ontario Street East, at the foot of Ontario Street East, in Streetsville, in Mississauga. The ruins are of a one-storey stone and brick building that was constructed in circa 1840.
The City of Mississauga designated the property, in 1992, under Part IV of the Ontario Heritage Act (By-law 360-92).
Heritage value
Located at the foot of Ontario Street on the banks of the Credit River, the Hyde Mill Ruins were significant to the establishment of both John Hyde's Ontario Mills and the first municipally-owned hydro-electric power plant.
The Hyde Mill Ruins reflect the significant role the milling industry had in the development of Streetsville and its contribution to hydro-electric power. It was the area's first hydro-electric station. Built in circa 1840 by American immigrant, John Hyde, it was one of the later mills to be established in Streetsville. When established the mills were at the height of technology and included a saw mill, grist mill and barracks for the workmen.
The success of John Hyde's Ontario Mills came to a halt when the mill was destroyed by fire in 1867. The site was revived in 1906 with the building of a dam across the Credit River and conversion of the mill to generate electricity. It was the first municipally-owned power plant and supplied Streetsville with hydro-electric power until 1943, when the village joined Ontario Hydro. The power plant continued to provide auxiliary power until 1960.
Of the original mill complex only the ruins of the stone walls remain today. The walls and foundation are of squared rubble, reinforced with both concrete and staggered brick. On the north elevation, openings for a door and two windows remain. The ruins serve as a reminder of the industrial heritage of the Credit Valley.
SourceCity of Mississauga By-law 360-92.
Character‑defining elements
Character defining elements that contribute to the heritage value of the Hyde Mill Ruins include its:
- location on the Banks of the Credit River
- one-storey stone and brick exterior
- door opening
- two window openings
End of the register’s text
Location
0, Ontario Street, City of Mississauga, Ontario, L5M, Canada
43.58638° N, 79.71674° W
Get directions (opens in a new tab)Being on the register doesn’t make a place open to visitors. Many are private homes or businesses; please view them from the street.
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From the Canadian Register of Historic Places, as last updated on December 12, 2025. The register’s text is shown word for word.