Previous studies have demonstrated that thinking dispositions and working memory are closely related to students' critical thinking ability. However, little is known about whether bidirectionality between thinking dispositions, working memory, and critical thinking ability exists in adolescence. This study, therefore, explored this aspect across two time points. Participants were 509 Chinese adolescents (mean age at Time 1 = 14.09 years; 59.7% girls). At Time 1, adolescents were administered the measures of thinking dispositions, working memory, and critical thinking ability. They were reassessed using these measures at Time 2 one year later. The results revealed a bidirectional longitudinal relationship between adolescents' thinking dispositions and critical thinking ability, suggesting that thinking dispositions at Time 1 predicted critical thinking ability at Time 2; critical thinking ability at Time 1 also predicted subsequent thinking dispositions in adolescents. Furthermore, working memory at Time 1 showed a larger predictive effect on critical thinking ability at Time 2 compared with thinking dispositions at Time 1. These findings underscore the role of early thinking dispositions and working memory in promoting adolescents' critical thinking ability.