The Third Wisconsin Legislature convened from January 9, 1850, to February 11, 1850, in regular session.

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

Senators representing odd 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 the first year of his second two-year term, having won re-election in the 1849 Wisconsin gubernatorial election.

Members of the Wisconsin Senate for the Third Wisconsin Legislature (19): Members of the Assembly for the Third Wisconsin Legislature (66):