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. There are deadlines for circulating petitions and filing nominating papers. Position on the ballot is according to 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. Before candidates are officially placed on the ballot, a week for filing objections or withdrawing nominating papers is given.
More specific information regarding a city election is generally available 30 days prior to an election and may be obtained by calling the City Clerk's Office at (630) 393-9427. For all other elections, the DuPage County Board of Elections may be contacted at (630) 407-5600.