The Thai food delivery market has reached maturity, with market value contracting by 1.0 percent in 2024. Retaining existing customers has therefore become more important than acquiring new ones. Meanwhile, no study has yet examined loyalty among educational personnel, a group with limited time and stable regular income in medium-sized cities. This research aimed 1) to investigate the level of service marketing mix (7Ps) factors and the level of customer loyalty toward food delivery services among educational personnel in Mueang District, Chumphon Province, and 2) to analyze the influence of service marketing mix (7Ps) factors on customer loyalty toward food delivery services in the same population. This quantitative research collected data through an online questionnaire from 400 educational personnel under the Chumphon Primary Educational Service Area Office 1 who had used food delivery services at least once within the past three months. A two-stage non-probability sampling procedure was employed, comprising convenience sampling through the distribution of the questionnaire via internal organizational communication channels, and purposive sampling based on predetermined selection criteria. Data were analyzed using descriptive statistics and multiple regression analysis with the Enter method at the .05 significance level. The findings revealed that: 1) the service marketing mix (7Ps) factors and customer loyalty were at a high level overall, and 2) the seven service marketing mix factors jointly explained 71.1 percent of the variance in customer loyalty (Adjusted R? = .711, F = 141.380, p < .001). Factors exerting a statistically significant positive influence at the .05 level, ranked from highest to lowest, were process (Beta = .305), physical evidence (Beta = .238), people (Beta = .149), and place (Beta = .103), whereas price, product, and promotion showed no statistically significant influence. These findings indicate that service delivery factors are more important in building customer loyalty than traditional marketing factors. Practitioners should therefore prioritize the design of the service delivery experience.