The Second Wisconsin Legislature convened from January 10, 1849, to April 2, 1849, in regular session.

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

Senators representing even numbered districts were serving the second year of their two-year term.

[1] The governor of Wisconsin during this entire term was Democrat Nelson Dewey, of Grant County, serving his first full year in office after winning election in the state's first gubernatorial election in May 1848, and taking office in June 1848.

Members of the Wisconsin Senate for the Second Wisconsin Legislature (19):[1] Members of the Assembly for the Second Wisconsin Legislature (66):[1][3][4]