Chronotype describes a person's general preference for mornings, evenings or neither. It is typically conceptualized as a continuous unidimensional spectrum from morningness to eveningness. Eveningness is associated with poorer outcomes across a myriad of physical and mental health outcomes. This preference for later sleep and wake times is associated with increased risk of depression, anxiety, and suicidal ideation and behaviors in both clinical and community samples. However, the mechanisms underlying the negative consequences of this preference for evenings is not fully understood. Previous research has found that sleep disturbances may act as a mediator of this relationship. The present study aimed to explore the associations between chronotype and affective outcomes in a community sample of young adults. Additionally, it aimed to investigate the potential role of insomnia as a mediator within these relationships. Participants (n = 260) completed an anonymous self-report survey of validated measures online which assessed chronotype, insomnia symptoms, and a range of affective outcomes (defeat, entrapment, stress, suicide risk, and depressive and anxious symptomology). Eveningness was associated with more severe or frequent experiences of these outcomes, with young adults demonstrating a preference for eveningness more likely to report poorer affective functioning and increased psychological distress. Mediation analysis found the relationship between chronotype and these outcome measures were partially mediated by sleep disturbances as measured by the well-validated Sleep Condition Indicator insomnia scale. Taken together, these findings add further evidence for the negative consequences of increased eveningness. Additionally, our results show that chronotype and sleep disturbances should be considered when assessing mental well-being. Implementing appropriate sleep-related behavior change or schedule alterations can offer a tool for mitigation or prevention psychological distress in young adults who report a preference for later sleep and wake times.