Study Objectives: To determine whether undiagnosed obstructive sleep apnea (OSA) and/or excessive daytime sleepiness are associated with symptomatic depression in Australian men. Methods: Participants were randomly selected, urban community dwelling men aged 40 to 88 years without a prior diagnosis of OSA. Clinically significant depressive symptoms were assessed using the Beck Depression Inventory-IA or Centre for Epidemiological Studies Depression Scale (2007-2010). A random sample of men (n = 788) undertook full at-home unattended polysomnography (Embletta X100, Broomfield, Colorado, United States) and completed the Epworth Sleepiness Scale questionnaire (2010-2012). Results: Undiagnosed severe obstructive sleep apnea (apnea-hypopnea index > 30 events/h) was associated with depressive symptoms (adjusted odds ratio = 1.98; 95% confidence interval [CI] 1.05-3.73; P =.036). However, a significant interaction was observed between obstructive sleep apnea and excessive daytime sleepiness (P =.03) such that individuals with OSA and excessive daytime sleepiness (Epworth Sleepiness Scale score of 10 or higher) exhibited the strongest associations with depression (mild-moderate apnea: adjusted odd ratio = 3.86; 95% CI 1.87-7.95; severe apnea: adjusted odd ratio = 4.82; 95% CI 1.42-16.35) when compared to individuals without apnea. Conclusions: Depressive symptoms in men were associated with undiagnosed OSA in the community. It is important that clinicians and primary care practitioners consider screening for depression in men with severe OSA and for OSA in men with depression. Screening for depression should also be considered in men with excessive daytime sleepiness regardless of OSA severity.