Little is known regarding the health and lifestyle behaviours of Australians of Lebanese ethnicity. The available evidence suggests that Australians of Lebanese ethnicity who were born in Lebanon reportedly have higher rates of cardiovascular disease-related and type 2 diabetes-related complications when compared with the wider Australian population. The aim of this study is to compare lifestyle behaviours of middle-Aged to older adults of Lebanese ethnicity born in Lebanon, Australia, and elsewhere to those of Australian ethnicity. Participants were 37,419 Australians aged ¿45 years, from the baseline dataset of The 45 and Up Study which included 4 groups of interest: Those of Australian ethnicity (n = 36,707) [Reference]; those of Lebanese ethnicity born in Lebanon (n = 346); 302 those of Lebanese ethnicity born in Australia (n = 302); and those of Lebanese ethnicity born elsewhere (n = 64). Multilevel logistic regression was used to examine the odds of those of Lebanese ethnicity reporting suboptimal lifestyle behaviours (insufficient physical activity, prolonged sitting, smoking, sleep duration, and various diet-related behaviours) relative to those of Australian ethnicity. Multilevel linear regression was used to examine the clustering of suboptimal lifestyle behaviours through a lifestyle index' score ranging from 0±9 (sum of all lifestyle behaviours for each subject). The lifestyle index score was lower among Lebaneseborn (-0.36, 95% CI -0.51, -0.22, p < 0.001) and Australian-born (-0.17, 95% CI -0.32, -0.02, p = 0.031) people of Lebanese ethnicity in comparison to those of Australian ethnicity. Those of Lebanese ethnicity born in Lebanon had higher odds of reporting suboptimal lifestyle behaviours for physical activity, smoking, and sleep duration, and lower odds of reporting optimal lifestyle behaviours for sitting time, fruit, processed meat, and alcohol consumption, when compared with those of Australian ethnicity. Differences in the individual lifestyle behaviours for those of Lebanese ethnicity born in Australia and elsewhere compared with those of Australian ethnicity were fewer. Lifestyle behaviours of those of Lebanese ethnicity vary by country of birth and a lower level of suboptimal lifestyle behaviour clustering was apparent among Lebanese-born and Australian-born middle-Aged to older adults of Lebanese ethnicity.