State Sen. Vincent Sheheen, D-Kershaw, formally announced his candidacy for governor Wednesday.
"I've been traveling South Carolina for the last few months, and I've spoken to hundreds of South Carolinians who are ready to restore leadership and vision to our state," said Sheheen, who has been raising money and campaigning for months.
The Camden Democrat has raised more than $780,000 in his bid for his party's nomination, more than any other Democratic contender.
Party primaries will be held in June.
The four other Democrats who have announced their candidacies are: Columbia attorney Dwight Drake, state Sen. Robert Ford of Charleston, Charleston attorney Mullins McLeod and state schools Superintendent Jim Rex.