Background: Literature pertaining to the prevalence of obstructive sleep apnoea (OSA) and sleep quality among Indigenous Australian children is sparse. This study assessed various sleep related parameters and outcomes between Indigenous and non-Indigenous Australian children. Methods: Children referred to the sleep health service in the Northern Territory of Australia for a clinically suspected sleep disorder between 2015 and 2021 were included in this study. Self-reported sleep measures alongside polysomnography data were assessed and compared between these two diverse ethnic population. Results: Of the 671 sleep studies assessed, 121 (18%) were from Indigenous children. The majority of patients were male (61%), with a median age of 5.7 (3.5, 8.9) years, and body mass index (BMI) in the normal range (57%). Indigenous children were significantly older (median 7.2 years (4.5, 11.9), with a higher BMI (p = 0.005) and a greater proportion living in very remote locality (14% vs. 6% non-Indigenous, p = 0.001). Indigenous children had higher Paediatric Daytime Sleepiness Scale scores (p = 0.001), higher screen use before bed (p = 0.005), later bedtimes (p = 0.001) and reduced total sleep time (p = 0.034) compared to non-Indigenous children. Prevalence of OSA was higher in Indigenous children (55% vs. 48%) and with greater severity compared to non-Indigenous children. Conclusions: In this study, OSA was more prevalent and more severe in Indigenous children than their non-Indigenous peers. However, this may not necessarily be extrapolated to the general Indigenous paediatric population. Sleep hygiene and sleep quantity was also decreased further impacting adequate sleep. This highlights the importance of identifying and managing these addressable parameters and for targeted interventions.