Breast anthropometry, an essential aspect of biological anthropology, examines the scientific measurement of breast size and its descriptive indices. Understanding the relationship between breast size and Body Mass Index (BMI) is vital for both anthropological research and healthcare. This cross-sectional observational study aimed to investigate the correlation between breast size and BMI among females in Ado-Odo-Ota Local Government Area. Data were collected from 210 female residents aged 12-70 years, excluding those with congenital breast anomalies or prior breast surgeries. Anthropometric measurements including breast circumference, underbust girth, shoulder to nipple length, inter-nipple distance, and breast projection were recorded alongside weight and height measurements. Statistical analyses, including Pearson’s correlation and Chi-square tests, were conducted to explore the associations between breast anthropometry and BMI. Results revealed significant positive correlations between breast size parameters (breast circumference, underbust circumference, inter-nipple distance, shoulder-nipple length, and breast projection) and BMI (p < 0.001). Regression analysis indicated that breast circumference significantly predicted BMI (p < 0.001). Additionally, a strong correlation was observed between weight and breast anthropometry measures, suggesting a substantial impact of weight on breast morphology. However, no significant association was found between height and certain breast measurements, although underbust circumference, shoulder-nipple length, and breast circumferences exhibited positive correlations with height. These findings contribute to our understanding of the complex interplay between anthropometric parameters and breast morphology, emphasizing the importance of considering multiple factors, including BMI and weight, in assessing breast size variations. Such insights are crucial for both anthropological studies and healthcare interventions, providing a foundation for informed discussions on body composition, health risks, and preventive strategies. Further interdisciplinary investigations are warranted to elucidate the nuanced relationship between breast size, BMI, and overall health outcomes