This study explores the potential of enriching used edible oils with distillation residual rosemary powder (DRRP) to enhance their quality and stability. Physico-chemical and thermal analyses were performed to assess the oils' chemical quality indices. The results revealed that enrichment with 1%, 5%, and 10% DRRP significantly minimized acid index degradation, maintaining stability even after 11 days of storage. Additionally, the enriched oils demonstrated improved compliance with food quality standards. Thermal analysis further showed that DRRP enrichment markedly enhanced resistance to thermal degradation at elevated temperatures compared to virgin oil (positive control) and untreated used oil (negative control). These findings underscore the protective properties of DRRP, presenting a promising strategy to extend the shelf life of used oils in the food industry while promoting sustainable practices.