Wisconsin's 12th Senate district

The 12th Senate District of Wisconsin is one of 33 districts in the Wisconsin Senate. Located in northern Wisconsin, the district comprises Florence, Forest, Langlade, Lincoln, Marinette, Oneida, and Vilas counties, and parts of northern Oconto County, northwest Shawano County, and northeast Marathon County. It contains the cities of Antigo, Eagle River, Marinette, Merrill, Peshtigo, Rhinelander, and Tomahawk.

Current elected officials
Mary Felzkowski is the senator representing the 12th district. She was first elected in the 2020 general election. She previously served 8 years in the State Assembly.

Each Wisconsin State Senate district is composed of three Wisconsin State Assembly districts. The 12th Senate district comprises the 34th, 35th, and 36th Assembly districts. The current representatives of those districts are:
 * Assembly District 34: Rob Swearingen (R–Rhinelander)
 * Assembly District 35: Calvin Callahan (R–Wilson)
 * Assembly District 36: Jeffrey Mursau (R–Crivitz)

The 12th Senate district is split between two congressional districts. The portion of the district in Florence, Forest, Langlade, Oneida, Vilas, Lincoln, and Marathon counties falls within the Wisconsin's 7th congressional district, which is represented by U.S. Representative Tom Tiffany; the remainder of the district, which falls within Marinette, Oconto, Menominee, and Shawano counties, is in Wisconsin's 8th congressional district, which is represented by U.S. Representative Mike Gallagher.

Past senators
Past senators include:

Note: the boundaries of the district has changed repeatedly over history. Previous politicians of this district have represented a completely different geographic area, due to redistricting. The district definitions for the given era are specified in the "District definition" column.