Limited research has examined the well‐being of international preschool teachers, while intervention targeting their well‐being is even rarer. The objective of this study was to examine the effectiveness of a 2‐month EASP (i.e., Early Advancement in Social‐Emotional Health and Positivity) positive psychological intervention program based on the PROSPER—which stands for positivity, relationship, outcome, strength, purpose, engagement, and resilience– framework on international preschool teachers' well‐being in Hong Kong. Eighty‐three teachers (Mage = 34.44 years, SD = 8.43, range = 19–53; female = 95.18%) were randomly assigned to the intervention (n = 44) and waitlist control groups (n = 39). Teachers completed survey measures of PROSPER well‐being at baseline and after the intervention. The results of the multivariate regression analyses revealed that the intervention did not have significant overall effects on the PROSPER well‐being, Wilks' lambda F(7, 56) = 1.28, p = 0.28, η2 = 0.14. Yet, findings of univariate analyses suggested the intervention yielded significant medium effects on participants' relationship, outcome, strength and engagement (b = 0.26 to 0.45, 95% CI [0.04, 0.95], p = 0.02 to 0.03, η2 = 0.07 to 0.08). The findings underscore the practical utility of the PROSPER framework in supporting international preschool teachers' well‐being but, at the same time, highlight the need to further examine how cultural variations might implicate its effectiveness.