The Fortieth Wisconsin Legislature convened from January 14, 1891, to April 25, 1891, in regular session.

[1] They met again for two special sessions in June 1892 and October 1892 to pass redistricting laws.

The extra sessions were necessitated by court cases which threw out the Legislature's previous attempts at redistricting.

Senators representing odd-numbered districts were newly elected for this session and were serving the first two years of a four-year term.

[1] The governor of Wisconsin during this entire term was Democrat George Wilbur Peck, of Milwaukee County, serving a two-year term, having won election in the 1890 Wisconsin gubernatorial election.