The Forty-Fifth Wisconsin Legislature convened from January 9, 1901, to May 15, 1901, in regular session.^[1]

Senators representing even-numbered districts were newly elected for this session and were serving the first two years of a four-year term. Assembly members were elected to a two-year term. Assembly members and even-numbered senators were elected in the general election of November 6, 1900. Senators representing odd-numbered districts were serving the third and fourth year of a four-year term, having been elected in the general election of November 8, 1898.^[1]

• January 7, 1901: Inauguration of Robert M. La Follette as the 20th Governor of Wisconsin. He was the first governor of Wisconsin to have been born in Wisconsin.
• January 22, 1901: Queen Victoria of the United Kingdom died and was succeeded by her son, Edward VII.
• March 4, 1901: Second inauguration of U.S. President William McKinley.
• September 6, 1901: President William McKinley was shot by anarchist Leon Czolgosz in Buffalo, New York. He would die 8 days later.
• September 14, 1901: Vice President Theodore Roosevelt was sworn in as the 26th President of the United States, following the death of President William McKinley.
• October 1, 1901: The Wisconsin Legislative Reference Library was opened in the State Capitol under chief Charles McCarthy. The library was the first of its kind and was a model for the Congressional Research Service.
• April 2, 1902: The Electric Theatre, the first movie theater in the United States, opened in Los Angeles, California.
• May 11, 1902: Wisconsin Lieutenant Governor Jesse Stone died of stomach cancer at Watertown, Wisconsin.
• June 29, 1902: The federal Spooner Act, named for Wisconsin's U.S. senator John Coit Spooner, was signed by President Theodore Roosevelt, to purchase land that would become the Panama Canal Zone.
• July 1, 1902: The Philippine Organic Act was signed by President Theodore Rooselvelt, bringing an end to the Philippine–American War.
• November 4, 1902: Wisconsin general election:
  • Robert M. La Follette re-elected as Governor of Wisconsin.
  • Voters approved an amendment to the Wisconsin constitution to authorize a general banking law and remove previous referendum requirements for banking laws.
  • Voters approved an amendment to the Wisconsin constitution to convert the Superintendent of Public Instruction to a nonpartisan, 4-year office, with pay set by legislation.
  • Voters approved an amendment to the Wisconsin constitution to prohibit individuals, companies, political committees, and other entities from providing any free pass, free transportation, or free communication to any officer of state, local, or county government in Wisconsin.

• April 12, 1901: An Act to apportion and district anew the state of Wisconsin into assembly districts, 1901 Act 164.
• May 6, 1901: An Act to apportion and district anew the state of Wisconsin into senate districts, 1901 Act 309.
• May 13, 1901: An Act to apportion and district anew the state of Wisconsin into congressional districts, 1901 Act 398.
• Joint Resolution agreeing to a proposed amendment to article XI of the constitution of the state of Wisconsin, giving the legislature power to pass a general banking law, 1901 Joint Resolution 2. This was the second required legislative approval of this amendment, which was then ratified by voters in November 1902.
• Joint Resolution agreeing to constitutional amendment, 1901 Joint Resolution 3. Amendment (1) converting the Superintendent of Public Instruction of Wisconsin from a political to nonpartisan office, (2) moving the elections for superintendent from Fall to Spring, (3) changing the term from two years to four years, (4) moving inauguration from the first Monday in the January following the election to the first Monday in the July following the election, and (5) enabling the Legislature to set the pay of the superintendent through law. This was the second required legislative approval of this amendment, which was then ratified by voters in November 1902.
• Joint Resolution for the submission of an amendment to section 1 of article VII of the constitution relating to the justices of the supreme court, 1901 Joint Resolution 8. Proposed adding two more justices to the Wisconsin Supreme Court, and proposing a process to determine the chief justice when two justices held equal seniority.
• Joint Resolution agreeing to a proposed amendment to article XIII of the constitution of the state of Wisconsin, to prohibit the pass system, 1901 Joint Resolution 9. This was the second required legislative approval of this amendment, which was then ratified by voters in November 1902.
• Joint Resolution providing for an amendment of section 23, article IV of the constitution and for separate county government in certain counties, 1901 Joint Resolution 12. Suggested an amendment to allow the Legislature to establish a separate system of county government that could be applied to creating new counties around cities with populations greater than 100,000.

• 1st Regular session: January 9, 1901 – May 15, 1901