This study was designed to examine the mediator role of resilience in the relationship between chronotype and mental toughness in adolescents.

The descriptive correlational study was completed with 342 high school students from one school in Türkiye (mean age 17.25±1.11 years). Data were collected with the Morningness–Eveningness Scale for Children, Child and Youth Resilience Measure, and Mental Toughness Scale for Adolescents. Hierarchical regression analyses with PROCESS Model 4 were used to evaluate the mediator effect.

It was observed that the morning chronotype tendency increased resilience (p < 0.001) mental toughness (p < 0.001). Higher resilience led to increased mental toughness. When the mediation effect was examined, resilience was a full mediator in the relationship between chronotype characteristics and mental toughness (β=0.396; p = 0.000).

According to these results, a morning chronotype tendency in adolescents increases their resilience and, therefore, mental toughness. These results suggest that effective methods for enhancing mental toughness in adolescents should be multifaceted. Additionally, it highlights the importance of identifying and regulating chronotype tendencies among adolescents, while also emphasizing the need to increase resilience in this demographic.