Exhibit 99.1 Southern First Reports Second Quarter 2026 Results Greenville, South Carolina, July 21, 2026 – Southern First Bancshares, Inc. (NASDAQ: SFST) (Southern First), today announced its financial results for the three months ended June 30, 2026. Strong loan growth and continued margin expansion drove year-over-year net interest income growth of 28%. Net income was $11.2 million and diluted earnings per share was $1.20, representing a $0.39, or 48% increase over the second quarter of 2025, and a sligh ...