Thirty-six South Carolina state legislative incumbents face primary contests in 2026, a 29% decrease from the number that faced challengers in 2024.

Twelve of the contested incumbents are Democrats, and 24 are Republicans. All of them are state representatives, as no state senators were up for election. South Carolina has 59 contested state legislative primaries in 2026, down 25% from 2024. Of these, 30 are for Democrats, and 29 are for Republicans. For Democrats, this is up from 27 in 2024, a 11% increase, though state senate incumbents were also up in 2024. Contested Republican primaries are down 44% from 52 in 2024.

In total, 297 major party candidates filed to run. One-hundred fifty-eight are Democrats, and 139 are Republicans. All 124 House seats are up for election. Six seats are open, meaning no incumbents filed. This means newcomers will make up at least 4% of the legislature next year. The average number of open seats each cycle from 2010 to 2024 was 12.