This study aimed to adapt and validate a Chinese version of the online self-regulated learning questionnaire (COSLQ) with Chinese junior secondary students in Hong Kong. A total of 716 students from six schools participated voluntarily in the study. Overall, the findings of this study supported the COSLQ's psychometric quality. The COSLQ subscales all demonstrated high internal consistency. Different measurement models were tested using confirmatory factor analysis. The results indicated that a 7-factor model best fit the data, suggesting that the participants could distinguish seven types of online self-regulatory strategies: goal setting, environment structuring, time management, effort regulation, cognitive/monitoring strategies, help seeking, and self-evaluation.