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Ontario Highway 403

Ontario Highway 403, officially King's Highway 403, is a 400-series controlled-access highway in Southern Ontario.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Ontario Highway 403, officially King's Highway 403, is a 400-series controlled-access highway in Southern Ontario. The route runs between Woodstock and Mississauga, connecting with Highway 401 at both ends, and passes through Hamilton and the Greater Toronto area. It serves as a major commuter and intercity corridor in the province.

Route description

Highway 403 is an east-west freeway in Southern Ontario that serves Woodstock, Brantford, Hamilton, Burlington, Oakville, and Mississauga. It branches from Highway 401 at both ends and shares a long segment with the QEW in Halton Region.

History

The 403 designation first appeared in 1963, but the route was built in stages over several decades. The final section opened on August 15, 1997, completing the through route between Woodstock and Mississauga.

Local names

Within Hamilton, Highway 403 is also called the Chedoke Expressway. Other sources note a named parkway segment between Woodstock and Burlington, but the highway is best known publicly as Highway 403.

Role in transportation

The highway provides a southern alternative to Highway 401 and a direct route between southwestern Ontario and the Toronto area. It is a major commuter and intercity corridor in the province.

Key facts

  • Highway 403 is a controlled-access freeway linking Woodstock and Mississauga.
  • It connects with Highway 401 at both ends and passes through Hamilton and the Greater Toronto area.
  • The highway runs concurrently with the Queen Elizabeth Way for about 22 km between Burlington and Oakville.
  • First designated in 1963, the full route was completed on August 15, 1997.
  • It serves as a major commuter and intercity corridor in Southern Ontario.
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Canadian context

Highway 403 is a major Ontario freeway used by commuters and freight traffic in the Greater Toronto and southwestern Ontario corridor, making it significant for Canadian road transport.

Frequently asked questions

What is Ontario Highway 403?
It is a 400-series controlled-access highway in Ontario that runs from Woodstock to Mississauga and connects with Highway 401 at both ends.
What is Highway 403 officially called?
Its official name is King's Highway 403.
Which cities does Highway 403 pass through?
It passes through or near Woodstock, Brantford, Hamilton, Burlington, Oakville, and Mississauga.
When was Highway 403 completed?
The full route was completed on August 15, 1997, when the Brantford-to-Ancaster section opened.
Does Highway 403 share any route with the QEW?
Yes. It runs concurrently with the Queen Elizabeth Way for about 22 kilometres between Burlington and Oakville.

References

  1. Wikipedia — https://en.wikipedia.org/wiki/Ontario_Highway_403
    Supports: Official and common names, route endpoints, Hamilton/Chedoke Expressway name, QEW concurrency, 1963 designation, 1997 completion.
  2. Wikidata — https://www.wikidata.org/wiki/Q2872845
    Supports: Controlled-access highway in Ontario, Canada; length 125.2 km; alternate names.
  3. The Highways of Hamilton — http://www.andrewturnbull.net/on403.html
    Supports: Route function, Hamilton alignment, 1997 opening, general historical context.
  4. The King's Highways of Ontario — https://www.thekingshighway.ca/Highway403.htm
    Supports: Historical development, completion in stages, role as southern alternative to Highway 401.