Jenny Honeycutt (R) defeated Mark Smith (R) in the Republican primary runoff for South Carolina's 1st Congressional District on June 23, 2026. Honeycutt and Smith were the top two finishers in the June 9 primary. Honeycutt received 22.1% of the primary vote and Smith received 18.0%. They advanced to a runoff after neither received more than 50% of the vote.
Both Honeycutt and Smith released new campaign ads after advancing from the primary. In a post-primary campaign ad, Honeycutt said, "I'm fighting to protect our home and our way of life. Unlike my opponent, I'm not running for a title. I'm running to serve you." A Smith campaign ad released after the primary said, "Jenny Honeycutt cast the deciding vote on a $4 billion tax hike. Mark Smith voted to cut your income taxes."
Incumbent Nancy Mace (R) ran for governor rather than seeking re-election. This was the first election in the 1st District without an incumbent since 2013.
