This study aimed to compare the effectiveness of Reality Therapy and Solution-Focused Therapy on cognitive emotional self-regulation and emotional distress in adolescent girls without mothers. The study employed a pretest-posttest-follow-up design. In this semi-experimental study, a total of 45 high school girls in Tehran who had lost their mothers and met the inclusion criteria were selected through convenience sampling in 2024. Participants were assessed before, after, and two months following the interventions using the Cognitive Emotion Regulation Questionnaire and the Distress Tolerance Scale. Data were analyzed using multivariate analysis of covariance (MANCOVA). The findings revealed that Reality Therapy significantly improved quality of life, cognitive emotional self-regulation, and emotional distress in comparison to the control group. Additionally, participants in the Solution-Focused Therapy group also demonstrated significant improvements in cognitive emotional self-regulation and emotional distress compared to the control group. However, no significant difference was found between the Reality Therapy and Solution-Focused Therapy groups in their effects on cognitive emotional self-regulation and emotional distress. These results suggest that both therapeutic approaches are similarly effective in enhancing cognitive emotional regulation and reducing emotional distress in motherless adolescent girls. Accordingly, either approach may be beneficial in supporting the psychological well-being of this vulnerable population.