The Republican Party nominated State Senator Troy Balderson for the seat while the Democratic Party nominated Franklin County Recorder Danny O'Connor.

Balderson led O'Connor in preliminary results; however, the race was not officially called on election night.

[2] The outstanding ballots did not change the margin enough to trigger an automatic recount, so Balderson was declared the winner on August 24.

[3] On October 19, 2017, nine-term incumbent Republican representative Pat Tiberi announced that he would leave office before January 31, 2018, in order to lead the Ohio Business Roundtable.

Ohio's 12th congressional district at the time was located in the central portion of the state and included all of Delaware, Licking, and Morrow counties, as well as portions of Franklin, Marion, Muskingum, and Richland counties.