State Trunk Highway 45
Route information
Maintained by WisDOT
Existed	1918–1934
Location
Country	United States
State	Wisconsin
Highway system
Wisconsin State Trunk Highway System Interstate US State Scenic Rustic
← US 45 → WIS 46

State Trunk Highway 45 (often called Highway 45, STH-45 or WIS 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 from Red Wing, Minnesota to Ellsworth, WIS 65 and WIS 35 up to Hudson
• Highway 45 from 1923 to 1934, currently routed as Highway 34
• For the highway in Wisconsin numbered 45 since 1934, see U.S. Highway 45.