This study investigated academic and environmental predictors of national licensing examination success among physical therapy graduates in Thailand, examining overall academic achievement, domain-specific competencies (Code 01: Law/Ethics/Administration; Code 02: Techniques; Code 03: Clinical), admission pathway, and COVID-19-related online-learning disruption. This retrospective cohort study analyzed 342 graduates (2020–2023) using multivariable logistic regression and Pearson correlation, with GPA-based predictors rescaled per 0.1-point increase. Undergraduate GPAX and Code 02/03 grades were the strongest positive predictors of both first-attempt and annual licensing success (adjusted OR range 1.35–1.74, all p < 0.001). Online-learning duration reduced first-attempt odds by 24% (OR = 0.757, p = 0.036) but did not affect annual success, while TCAS admission round was a significant negative predictor of first-attempt success only in the model excluding domain-specific scores (OR = 0.671, p = 0.011); Code 01 score was not significant in any model. These findings indicate that domain-specific academic performance, rather than general achievement or admission pathway, was the strongest predictor of licensing success, underscoring the value of early monitoring of coursework performance for identifying at-risk students.