The 1873 United States Senate election in Wisconsin was held in the 26th Wisconsin Legislature on Incumbent Republican U.S. senator Timothy O. Howe was re-elected on the first ballot, becoming the first three-term U.S. senator from Wisconsin.
At the start of the 1873 term, Republicans held majorities in both chambers of the Wisconsin Legislature, and were easily able to re-elect their incumbent U.S. senator. His re-election was considered a foregone conclusion in newspapers, and there doesn't appear to have been any other candidates for the Republican nomination.
The 26th Wisconsin Legislature met in joint session on January 22, 1873, to elect a U.S. senator. The voting was almost entirely along party lines, with five Democrats absent. Of the 128 in attendance, Timothy O. Howe received the votes of all but one of the Republican legislators, winning the election.