The Wisconsin Idea, in United States History, was a series of political reforms of the late 19th century and early 20th century whose strongest advocate was Robert M. La Follette, Sr., governor of (1901-1906) and senator from (1905-1925) Wisconsin .

These proposed reforms, all of which were eventually adopted, included:

• Primary elections, allowing the rank-and-file members of a political party to choose its nominees rather than caucuses usually dominated by political bosses
• Workers' compensation, allowing workers injured on the job to receive a fixed payment in compensation for their injuries and related expenses rather than forcing them to go to court against their employers, which at the time was extremely difficult and had little realistic chance of success
• State regulation of railroads in addition to the federal regulation imposed by the Interstate Commerce Commission
• Direct election of United States Senators as opposed to the original method of their selection by the state legislatures, eventually ratified as the Seventeenth Amendment to the United States Constitution.
• "Progressive" taxation, where the wealthier pay a higher rate of tax than the less-affluent, made possible on the federal level in part by the adoption of the Sixteenth Amendment to the United States Constitution

Adoption of these reforms marked the high point of the Progressive Era.