This study aims to develop a new scale called self-goal-directed social media usage (S-GSMU), test its reliability and validity, and examine the relationships among proactive personality (PP), S-GSMU, and online holiday purchase intention (OHPI), focusing on a gender-specific moderated and moderated-mediation model. The study seeks to address gaps in understanding trait- and gender-based online consumer decision-making in the hospitality and tourism industry. Data were collected through online surveys from 228 hospitality and tourism students (Study 1) and 383 tourism educators who were customers (Study 2) in Türkiye. To evaluate the proposed model and scale, the study performed content and construct validity analyses, reliability testing, and hypothesis testing through mediation and moderated mediation analyses. Study 1 developed the S-GSMU scale. Study 2 validated this scale and found that PP’s impact on S-GSMU and OHPI, as well as S-GSMU’s effect on OHPI, was significant. Additionally, S-GSMU was found to mediate the relationship between PP and OHPI. Moreover, gender was shown to strengthen the effects of PP on both S-GSMU and OHPI, and to enhance S-GSMU’s mediating role in the PP-OHPI relationship, with women playing a key role in these effects. The study highlights the gender-specific dynamics with the role of PP and S-GSMU in shaping OHPI, offering practical insights for tailored tourism marketing strategies.