This study focused on mental health and fatigue in elite university student-athletes competing in badminton at the national level, comparing them with control university students and examining related factors. Among university athletes, anxiety and depression showed a moderately negative correlation with life satisfaction outside of sports, as determined by partial correlation tests adjusted for fatigue. Athletes demonstrated a 47% rate of anxiety and a 30% rate of depression. These values showed no significant difference from those of the anxiety (29%) and depression (21%) rates in a non-athlete university student sample. In addition, this study suggested that the evaluation of fatigue using a checklist of individual strength might produce low reliability and validity for elite university student-athletes in badminton. These exploratory findings highlight the importance of focusing on athletes’ overall life satisfaction and suggest the potential need for effective mental health interventions beyond sports. However, because of the exploratory nature of this study and the small sample size, further research is necessary to confirm these results.