1918 United States Senate election in Illinois

The 1918 United States Senate election in Illinois took place on November 5, 1918.

Incumbent Democrat J. Hamilton Lewis lost reelection to Republican Medill McCormick.

Election information
The primaries and general election coincided with those for House and those for state elections. The primaries were held September 11, 1918.

This was the first election for this U.S. Senate seat to be held after the Seventeenth Amendment to the United States Constitution went into effect, and was therefore the first time that this seat faced a popular election.

Candidates

 * James Hamilton Lewis, incumbent U.S. senator
 * James O. Monroe, attorney and perennial candidate
 * James Traynor

Candidates

 * Alfred E. Case
 * George Edmund Foss, U.S. congressman
 * Medill McCormick, U.S. congressman
 * Patrick H. O'Donnell
 * William Hale Thompson, mayor of Chicago

Candidates

 * William Bross Lloyd, attorney and activist

Candidates

 * John M. Francis (Socialist Labor)
 * J. Hamilton Lewis (Democrat), incumbent U.S. senator
 * William Bross Lloyd (Socialist), attorney and activist
 * Medill McCormick (Republican), U.S. congressman
 * Frank B. Vennum (Prohibition Party), activist, capitalist, philanthropist, and 1912 candidate for Illinois treasurer