The 2020 United States presidential election in South Carolina was held on Tuesday, November 3, 2020, as part of the 2020 United States presidential election in which all 50 states plus the District of Columbia participated. South Carolina voters chose electors to represent them in the Electoral College via a popular vote, pitting the Republican Party's nominee, incumbent President Donald Trump, and running mate Vice President Mike Pence against Democratic Party nominee, former Vice President Joe Biden, and his running mate California Senator Kamala Harris. South Carolina has nine electoral votes in the Electoral College.

Charleston County is located in the U.S. state of South Carolina along the Atlantic coast. As of the 2020 census, the population was 408,235, making it the third-most populous county in South Carolina. Its county seat is Charleston. It is also the largest county in the state by total area, although Horry County has a larger land area. The county was created in 1800 by an act of the South Carolina State Legislature.