Wisconsin Highway 45
State Trunk Highway 45 was a number assigned to two different state highways in the U.S. state of Wisconsin:
- Highway 45 from 1917 to 1923, along the current route of U.S. Highway 63, Wisconsin Highway 65 and Wisconsin Highway 35 up to Hudson
- Highway 45 from 1923 to 1934, currently designated Wisconsin Highway 34
- For the highway in Wisconsin numbered 45 since 1934, see U.S. Route 45 in Wisconsin.