Reply #5: From the Ohio Secretary of State's web site (Blackwell) [View All]

[BattyDem]

Ohio has a 30-day voter registration requirement. If you register to vote by mail, your properly completed and signed registration application may be mailed to any of the afore mentioned locations, except the offices of the Bureau of Motor Vehicles or its deputy registrars, and must be postmarked not later than the 30th day before the first election in which you want to vote.

If you do not submit your registration application by mail, you must deliver the form to a county board of elections, the office of the Secretary of State, a public library, high school or vocational school, county treasurer’s office or designated agency not later than the registration deadline for the first election in which you want to vote.

http://www.sos.state.oh.us/sos/PublicAffairs/VoterInfoGuide.aspx?Section=14