Jeotgal, a traditional Korean salt-fermented food, has received insufficient research attention in its early stages because of the limited historical records before the Joseon period. This study explored ancient jeotgal culture by analyzing archaeological evidence from Baekje (Pungnap Toseong) and Silla (Wolseong district and Anapji). The findings revealed a highly organized system of production, distribution, and ritual use. At the Baekje site, various fish species were stored in large glazed vessels within underground royal facilities, suggesting large-scale, fermentation-based preservation. In Silla, Anapji wooden tablets (mokgan) document systematic management, including detailed production information. Regarding the terminology, Silla’s own words (Idu notation) ‘Josa (助史)’ used alongside ‘Hae (醢)’ identified jeotgal as a distinct food category, while the records of ‘Jusu-Josa (猪水助史)’ indicated that liquid-type jeotgal had already emerged as an independent product. Furthermore, the records of jeotgal transported from coastal areas to the capital revealed a state-led supply chain. Finally, fish remains in royal tombs, and ritual sites suggest that jeotgal had a significant ceremonial function beyond daily consumption. These results show that in ancient Korean society, jeotgal was strategically managed and integrated into the royal administrative and ritual systems.