Background Polycystic ovary syndrome (PCOS) is a prevalent metabolic and endocrine disorder affecting women of reproductive age, particularly those with obesity. This syndrome is characterized by clinical/biochemical hyperandrogenism and/or ovulatory dysfunction, which can result in infertility. Purpose To investigate the prevalence of PCOS in candidates for bariatric surgery and to examine the correlation between PCOS and sex hormones in women with obesity. Methods A retrospective study analyzed 577 bariatric surgery candidates from 2015 to 2021 using RStudio. Normally distributed data were expressed as x +/- s and compared with ANOVA or T-test, while the Kruskal-Wallis test was used for non-normal data. Count data, presented as M [Q1, Q3], were analyzed with the Chi-square test. Logistic regression identified influencing factors, with P < 0.05 indicating statistical significance. Results The findings of our study reveal that the prevalence of PCOS among bariatric surgery candidates stands at 14.04%. Conversely, high-density lipoprotein cholesterol (HDL-C) levels tended to decrease with higher BMI categories (P = 0.02). Compared to the non-PCOS group, the PCOS group exhibits lower age and HDL-C levels. Still, they showed significantly elevated HOMA-IR, fasting blood glucose (FBG), luteinizing hormone (LH), total testosterone (TT), and luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio (P < 0.05). The logistic regression analysis of PCOS indicates that, compared to the control group, those with FBG levels exceeding 7 mmol/L (OR = 2.28, 95% CI 1.19 to 4.37, P = 0.01) and individuals with TT levels greater than 2.01 ng/ml (OR = 2.36, 95% CI 1.23 to 4.71, P = 0.01) exhibited an increased risk of PCOS. Conclusion PCOS is highly prevalent among female bariatric surgery candidates. It is significantly associated with younger age, lower HDL, higher FBG, and elevated TT levels. These factors may also serve as indicators for evaluating PCOS improvement and assessing surgical outcomes postoperatively.