South Asians have become a sizable ethnic minority in Hong Kong with unique health and social needs often being overlooked. Elevated obesity risk among South Asians has been highlighted in high-income Western settings; however, relevant local evidence is scarce. This cross-sectional study aims to explore the obesity prevalence and related risk factors among South Asians in Hong Kong. Between June 2022 and February 2023, 535 South Asian adults were recruited via territory-wide health outreach services, and completed a survey and anthropometric measurements on height, weight, and waist circumference. In our female-dominated sample (84.1% female; mean age = 41.0 ± 12.3 years), the observed prevalence of general obesity (body mass index [BMI] [greater than or equal to] 27.5 kg/m[superscript 2] for South Asians) and abdominal obesity (waist-to-height ratio [WHtR] > 50%) were 60.2% and 89.4%, respectively. Results from multivariable linear regressions showed that mean BMI and WHtR were significantly higher among women and Pakistani individuals (and Nepalese individuals for BMI only) but lower among better educated and employed respondents. Apart from age, household size, and marital status as common risk factors, having a healthier diet and higher physical activity level were also associated with lower WHtR. Notably, the associations of female gender and Pakistani ethnicity were attenuated after adjustments for socioeconomic and lifestyle factors. In conclusion, there was a high prevalence of obesity in South Asian participants in this study. The identified risk and protective factors could inform targeted services and community-based weight management programs to mitigate obesity and its associated cardiometabolic risks in this fast-growing but vulnerable community.