In the state of Missouri, you must be a registered voter before you can vote. You must be a U.S. citizen, a resident of Missouri and 18 years of age by the day of the election. You cannot be declared incapacitated, be imprisoned, be convicted of a felony or misdemeanor related to voting or on probation or parole after a felony conviction.
Register to vote by filling out the application found at http://www.sos.mo.gov/elections/, at the office of the local election authority – Local Election Authority Contact Information, at any Department of Motor Vehicles office or state agency providing a service to the public (WIC, Social Services, etc.) The registration deadline is 5:00pm on the fourth Wednesday prior to the election.
When you register, your name will appear on the election register at your polling place. This allows you to sign in quickly when you arrive on Election Day.