Voter Registration in South Carolina:

In order to vote, South Carolina law requires one must first register to vote at least 30 days prior to the election. To be eligible to register in South Carolina you MUST:
-be a United States citizen
-be at least eighteen years old on or before the next election
-be a resident of South Carolina, this county and precinct
-not be under a court order declaring you mentally incompetent
-not be confined in any public prison resulting from a conviction of a crime
-have never been convicted of a felony or offense against the election
laws OR if previously convicted, have served the entire sentence,
including probation or parole, or have received a pardon for the conviction.

A citizen who wishes to register to vote can complete a voter registration application at their county board of voter registration.

Locations of county boards of voter registration