Ontario Highway 17
King's Highway 17, more commonly known as Highway 17, is a provincially maintained highway and the primary route of the Trans-Canada Highway through the Canadian province of Ontario. It begins at the Manitoba boundary, west of Kenora, and the main section ends where Highway 417 begins just west of Arnprior. A small disconnected signed section of the highway still remains within the Ottawa Region between County Road 29 and Grants Side Rd. This makes it Ontario's longest highway.

The highway once extended even farther to the Quebec boundary in East Hawkesbury with a peak length of about . However, a section of Highway 17 "disappeared" when the Ottawa section of it was upgraded to the freeway Highway 417 in 1971. Highway 17 was not re-routed through Ottawa, nor did it share numbering with Highway 417 to rectify the discontinuity, even though Highway 417 formed a direct link between the western and eastern sections of Highway 17. However, from East Hawkesbury to Ottawa, Highway 17 retained the Trans-Canada Highway routing and signs until it met up again and merged with Highway 417 until 1997 when Highway 17 through Ottawa was downgraded. The Trans-Canada Highway designation now extends along all of Highway 417.

Ontario Highway 17 is a very important part of the national highway system in Canada, as it is the sole highway linking the eastern and western regions of the country. Although other small roads connect the province of Ontario with the province of Manitoba, it is the only major highway that links the two, making it a crucial section of Canada's primary commercial and leisure route for all traffic travelling between Canada's largest cities, from Toronto and Montreal in the east to Calgary and Vancouver in the west.
Q5760022
provincially maintained highway
LOC
Q1061576
Trans-Canada Highway
LOC
Q2879
Canadian province
Concept
Q1904
Ontario
LOC
Q1948
Manitoba
LOC
Q993714
Kenora
LOC
Q2024660
Highway 417
LOC
Q543997
Arnprior
LOC
Q176
Quebec
LOC
Q3128766
East Hawkesbury
LOC
Q16
Canada
LOC
Q1904
Ontario
LOC
Q1948
Manitoba
LOC
Q172
Toronto
LOC
Q340
Montreal
LOC
Q36312
Calgary
LOC
Q24639
Vancouver
LOC
Q2024654
Ontario Highway 17
LOC
1971-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1971
DATE
1997-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1997
DATE
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17
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17
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29
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17
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17
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+17^^http://www.w3.org/2001/XMLSchema#decimal
17
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17
NUMBER
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17
NUMBER
+17^^http://www.w3.org/2001/XMLSchema#decimal
17
NUMBER
highway system
highway system
located in the administrative territorial entity
terminus location
country
located in the administrative territorial entity
located in the administrative territorial entity
located in the administrative territorial entity
terminus location