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July 31, 2026Short & citedBlog
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Civic Brief • Canada Notes

Ontario Highway 403

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

Updated July 31, 20261 min readCited sources

Ontario Highway 403 is a 125.2 km controlled-access freeway connecting Woodstock to Mississauga. It serves as a major east-west corridor through Hamilton and the Greater Toronto Area.

What it is

Officially named King's Highway 403, this 400-series highway runs between Woodstock and Mississauga, linking with Highway 401 at both ends. It passes through Hamilton, where it is also known as the Chedoke Expressway, and shares a 22 km concurrent segment with the Queen Elizabeth Way between Burlington and Oakville.

Key details

The Highway 403 designation first appeared in 1963 on a short freeway stub near Burlington. The full route was completed on August 15, 1997, when the Brantford-to-Ancaster section opened. It provides a southern alternative to Highway 401 and a direct route between southwestern Ontario and the Toronto area.

Why it matters

Highway 403 is a vital commuter and intercity corridor for Southern Ontario, carrying significant freight and passenger traffic. Its completion in 1997 improved connectivity for cities like Brantford, Hamilton, and Mississauga, supporting economic activity in the Greater Toronto and Hamilton Area.

In short

  • 125.2 km freeway from Woodstock to Mississauga
  • Connects with Highway 401 at both ends
  • Shares 22 km with the QEW in Halton Region
  • Completed in 1997 after decades of staged construction
Canadian angle

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.

Quick 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.
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.

Sources

  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.