The following highways are numbered 923:
| Preceded by 922 | Lists of highways 923 | Succeeded by 924 |
King's Highway 109, or Highway 109, is a former provincial highway in Ontario. It was used on two separate, unrelated routes during the 1950s and 1960s:
Secondary Highway 500, commonly referred to as Highway 500, was a secondary highway in the Canadian province of Ontario which was first designated in 1956. Its route was renumbered in 1964, becoming:
Secondary Highway 514, commonly referred to as Highway 514, was a secondary highway in the Canadian province of Ontario. It was used on two separate routes from the 1950s to the 1990s:
