Objective: Hirsutism is characterized by excessive terminal hair growth in a male-like pattern in women and globally affects approximately 5-10% of women within their reproductive age. This research seeks to investigate the association between hirsutism and body mass index (BMI) among women and adolescents in Rivers State University. Methodology: This research was carried out at Rivers State University (RSU), Port Harcourt, Nigeria. The study population consisted of female students and staff aged 15–40 years. Hirsutism was assessed using the Modified Ferriman–Gallwey (mFG) scoring system. Each of the nine body regions (upper lip, chin, chest, upper abdomen, lower abdomen, upper back, lower back, upper arm, thigh) were examined and assigned a score from 0 to 4. A total mFG score ≥ 8 was used to define clinical hirsutism, with consideration of ethnic-specific cutoffs (e.g., ≥ 9 for African populations). A digital weighing scale, a stadiometer, a meter rule and a digital vernier caliper were used to measure the weight, height, thumb and foot lengths. Results: The correlation analysis revealed a very weak negative association between BMI and hirsutism severity (r = –0.013, p = 0.791). This relationship was not statistically significant, indicating that BMI did not have a meaningful linear association with Ferriman–Gallwey Scores in the study population. Conclusion: In this University-based sample, hirsutism, though common, was not significantly associated with BMI.