Souline is a rare French name of uncertain origin. It is usually read either as a variant of the French Soline and Solène, which go back to the Latin sollemnis, "solemn" or "ceremonial", or as a southern French name recalling the sun, souleu in Provençal, which would give it the sense "little sun". The name did not appear in American data at all until 2020, jumped to number 2182 in 2021 and has stayed in the mid-2000s since, ranking number 2454 in 2025 with 73 girls.