Research has shown that the triarchic model of grit scale (TMGS)—a measure that assesses tendency to show perseverance, passion, and adaptability for long-term goals—has been valid in different contexts such as the Philippines, Japan, Poland, mainland China, and the United States. However, there is limited research on the validity of this scale in Hong Kong. Against this backdrop, this research examined the structural, convergent, and criterion-related of the TMGS among secondary school students in Hong Kong. A total of 298 secondary school students in Hong Kong participated in this study. Confirmatory factor analysis (CFA) was used to evaluate the structural validity of the three-factor model of grit. Correlational analysis was conducted between grit's dimensions and school satisfaction to assess the criterion-related validity of this scale. CFA showed that the scores from the three-factor model of grit underpinned by perseverance of effort, consistency of interests, and adaptability to situations were valid and reliable. There was mixed evidence on the convergent validity of the scale based on the subscales’ composite reliability (CR) estimates. Whereas perseverance of effort and adaptability to situations were positively correlated to school satisfaction, consistency of interests was negatively linked to the said criterion variable. This research demonstrates the potential applicability of the TMGS in Hong Kong. Copyright © 2023 The Authors. Psychology in the Schools Published by Wiley Periodicals LLC.