Background: Sleep quality is an important determinant of health; so much so that the socio-economic and healthcare burden of poor sleep quality is alarming. In Malaysia, there is a shortage of sleep-quality studies conducted on Myanmar migrant workers, who comprise a significant proportion of the Malaysian workforce. Aims: To identify the prevalence and determinants of poor sleep quality among Myanmar migrant workers in Malaysia. Study Design: A cross-sectional study utilising systematic random sampling with replacement method. Methodology: The study was conducted on 216 Myanmar migrant workers. A questionnaire was used to detect the socio-demographic information, health status, socio-economic information and lifestyle factors, and the Pittsburgh Sleep Quality Index (PSQI) was used to measure sleep quality. Results: The prevalence of poor sleep quality was found in 62.5% of the study population. The factors significantly associated with poor sleep quality were body mass index (BMI) (OR = 0.462, 95% CI 0.225-0.950, P = 0.036), skill level (OR = 0.283, 95% CI 0.097-0.822, P = 0.020), shift work (OR = 3.393, 95% CI 1.456-7.908, P = 0.005), days worked per week (OR = 2.317, 95% CI = 1.022-5.252, P = 0.044), working hours per day (OR = 2.305, 95% CI = 1.134-4.685, P= 0.021) and work-related physical tiredness (OR = 2.304, 95% CI = 1.186-4.476, P = 0.014). Conclusions: The findings highlight the burden and determinants of poor sleep quality among Myanmar migrant workers in Malaysia. The prevalence of poor sleep quality was 62.5% of the study population. Six factors were associated with poor sleep quality in this population: having a lower BMI (Body mass index), being engaged in upper skill level jobs, being a shift worker, working 6 to 7 days a week and more than 8 hours per day and having to spend more than 30 minutes on a daily commute.