Objectives: This study aimed to investigate the prevalence of sleep and mental health issues, the role of chronotype, and the relationship between these variables in Australian paramedics. Design: A cross-sectional study. Settings: Cross-sectional survey. Measurements: Paramedics were invited to complete an online survey to assess stress, posttraumatic stress disorder (PTSD), depression, anxiety, daytime sleepiness, insomnia, sleep quality, shift-work disorder, bruxism, obstructive sleep apnea, narcolepsy, chronotype, fatigue, and well-being. Participants: A total of 136 paramedics responded to the survey (age, 39.1 ± 12.1 years; 45.8% men and 54.2% women; 85.4% rotating shift-workers, 7% rural shift-workers, and 7.6% fixed rosters). Results: Paramedics reported significantly higher levels of depression symptoms, anxiety symptoms, fatigue, PTSD symptoms, insomnia symptoms, narcolepsy, and significantly poorer sleep quality and general well-being than norms from the general population of Australia and Western countries (all p < .05). From regression analyses, insomnia explained the greatest amount of variance in depression and anxiety scores, followed by fatigue and PTSD (adjusted R-squared for depression and anxiety models = .58 and = .44, respectively, p < .001). The majority of participants were intermediate chronotype (57%), followed by morning (32%) and evening type (11%). Evening chronotypes showed significantly higher depression scores (p < .001), anxiety (p < .05), PTSD symptoms (p < .05), poorer sleep quality (p < .05), and general well-being (p < .001) compared with morning types. Conclusion: Addressing sleep issues and matching chronotype to shift preference in paramedics may help to reduce depression, anxiety, and improve well-being.