The prevalence of overweight and obesity is rising dramatically worldwide, including in Australia. Therefore, the necessity of identifying the risk factors of overweight and obesity is pivotal. The main objective of this study is to investigate the influence of neighbourhood socio-economic circumstances and place of residence on obesity amongst Australian adults. This study has used nationally representative panel data on 183,183 person-year observations from 26,032 unique Australian adults from the Household, Income, and Labour Dynamics in Australia (HILDA). Random-effects logistic regression technique was employed to examine the relationships. The prevalence of overweight and obesity has been found at approximately 34% and 24%, respectively. The most striking result to emerge from the analyses is that adults living in the most socio-economic disadvantaged area were 2.04 times (AOR: 2.04, 95% CI: 1.57–2.65) and adults from regional cities of Australia were 1.71 times (AOR: 1.71, 95% CI: 1.34–2.19) more prone to be obese compared to their healthy counterparts. The prevalence of overweight and obesity is very high among Australian adults, especially those living in disadvantaged neighbourhoods and the regional cities. Unhealthy levels of BMI have costly impacts on the individual, the economy, and the health care system. Therefore, this study emphasises effective weight control strategies that can potentially tackle the obesity epidemic in Australia.