Warrenville's mayor, city clerk, and treasurer are elected at-large. Voters within each of the four wards elect an alderman who lives in their ward. Two aldermen are elected in each ward; one every two years.
The City of Warrenville holds consolidated elections every two years in April of odd years. During those years, nominating petitions for anyone wishing to run for office typically become available six months prior to the election. They can be picked up at the City Clerk's Office at City Hall during regular office hours. Deadlines for circulating petitions and filing nominating papers can be found on the election and campaign finance calendar published by the Illinois State Board of Elections prior to every election. A candidate's position on the ballot is determined by when the nominating papers are filed with the city clerk. If more than one candidate files simultaneously for the same office, a lottery is held. Petitions can be viewed by the public immediately following filing, and objections can be filed before candidates are officially placed on the ballot.
More information regarding elections can be found at the Illinois State Board of Elections publications website, the DuPage County Board of Elections website, or by calling the DuPage County Election Division at (630) 407-5600. Specific information regarding the City of Warrenville elections is generally available 30 days prior to an election and may be obtained by calling the City Clerk's Office at (630) 393-9427.