| Maintained by | City of Markham |
|---|---|
| Length | 6.125 km (3.806 mi) |
| Location | Markham, York Region |
| West end | &sq=Albert Einstein&lang=en&file=File:York_Regional_Road_1.svg){kind=small} Yonge Street |
| Major junctions | &sq=Albert Einstein&lang=en&file=File:York_Regional_Road_34.svg){kind=small} Bayview Avenue&sq=Albert Einstein&lang=en&file=File:York_Regional_Road_12.svg){kind=small} Don Mills Road / Leslie Street |
| East end | &sq=Albert Einstein&lang=en&file=File:York_Regional_Road_8.svg){kind=small} Woodbine Avenue (Continues as Esna Park Drive) |
| Construction | |
| Inauguration | 1800s |
John Street is an east-west collector and arterial road in the City of Markham, Ontario, Canada. It is one of the oldest roads in the Markham and forms the east-west backbone of the 200-year-old community of Thornhill.
The street originally ran east from Yonge Street across a tributary of the Don River, at which point it branched north to what is now Leslie Street and south on German Mills Road. This was a travelled road which did not match the alignment of any concession road or lot line and was constructed along the most convenient route to farms and mills to serve the needs of the inhabitants at that time.
John Street has had a major impact in shaping the community; the parallel 14th Avenue east-west concession road allowance (today named Green Lane) was never fully opened and Leslie Street still diverts from the route laid out by the township survey to join Don Mills Road near the former easterly end of John Street. However, in the late 20th century an extension of the street across Highway 404 to Woodbine Avenue, did ultimately link the street with 14th Avenue at Warden Avenue via Esna Park Drive and Alden Road, which themselves bypass another section of 14th Avenue.