The social information-processing (I-P) model states that cognition assumes several cognitive steps (encoding, interpretation, response access, and selection). It has been shown that anxious youth display deficits or distortions at various stages of the social I-P model. In response to ambiguous situations, they show threat perception and interpretation biases, choose maladaptive responses, and engage in greater levels of avoidance than do non-anxious youth. Acceptance and Commitment Therapy (ACT) is an empirically-supported treatment for anxious youth. It aims to increase mindfulness, acceptance, and cognitive defusion, and to decrease experiential avoidance. The mechanisms explaining the effectiveness of ACT processes suggest that they counteract automatic biased responses (which are characteristic of anxious children) during I-P stages. Specifically, research shows a strong association between mindfulness and attention, and between attention and decision-making. Therefore, it is likely that decreased mindfulness during the initial stages of I-P (i.e., during the encoding and interpretation phases) would predict ineffective solutions and explain associations between ineffective solutions and anxiety. The goal of this study was to examine ACT processes at various stages of the social I-P model to gain insight into the role that mindfulness, cognitive fusion/defusion, acceptance, and avoidance play during adolescents’ cognitive experiences in hypothetical situations. Self-report data of ACT variables, I-P variables, and anxiety were collected from 288 middle-school students of primarily Latinx backgrounds (87%). Findings indicated that across situations, mindfulness played a significant role in associations between youths’ I-P and anxiety; however, when characteristics of specific situations were considered, mindfulness was negatively related to threat interpretation and to maladaptive responses only in social situations. The results from this study highlight the protective role of mindfulness for anxious adolescents who tend to automatically interpret ambiguous social situations as threatening. Future mindfulness intervention researchers should strongly consider including measures of social adjustment when studying Latinx early adolescents, and clinicians should consider implementing mindfulness strategies with adolescents who struggle socially.