It travels south-to-north in the northeastern part of Wisconsin from an intersection with U.S. Highway 151 (US 151) approximately 1.5 miles (2.4 km) north of Brothertown, near the eastern shore of Lake Winnebago in Calumet County, to the Michigan state line at the Brule River approximately one mile (1.6 km) northeast of Nelma in Forest County, where it connects to M-73.

WIS 55 crosses Interstate 41 (I-41) and US 41 as it leaves Kaukauna and turns to go north, passing through Freedom.

In the forest, the highway crosses WIS 70 and goes through the town of Alvin and terminates at the Wisconsin-Michigan border on a bridge over the Brule River, where it continues as M-73.

Over the summer of 2018, a one-mile (1.6 km) section of WIS 55 at its interchange with I-41 in Kaukauna was reconstructed and four new roundabouts were added.

[3] In summer of 2023, the shoulder was widened in Alvin for bicycle access as part of a resurfacing project.