Objective College students with attention‐deficit/hyperactivity disorder‐related hyperactive/impulsive (HI) and/or inattentive (IA) symptoms may be at greater risk for suicidal behavior due to core and secondary symptoms that increase their potential to engage in behaviors that put them at risk for suicidal behavior. Consequently, the current study examined the moderating effect of combined HI/IA symptoms, in addition to independent HI and IA symptoms on the relationship between depressed mood and suicidal thoughts and behavior. Method A sample of 1,056 undergraduate students (61.5% female, 96.4% aged 18–24 years) provided self‐report ratings of mood, suicidal behavior (thoughts, self‐harm, attempts, and need for medical attention), and current HI/IA symptoms. Results Significant moderation effects were detected, such that greater HI/IA symptoms were associated with a stronger relationship between depressed mood and suicidal ideation and attempts, but not self‐harm. Current HI and IA symptoms significantly moderated the relationship between depressed mood and suicidal thoughts and suicide attempts, but did not moderate the relationship between depressed mood and self‐harm and need for medical attention. Conclusions The current findings suggest that the presence of combined HI/IA symptoms conveys increased suicide risk for depressed college students. Additionally, results suggest a complex relationship between independent HI and IA symptoms and severe suicidal outcomes.