Background Women’s support can improve uptake of voluntary medical male circumcision (VMMC). We assessed the level of women’s support for VMMC and associated factors in fishing settlements on the shores of Lake Victoria in Uganda, to inform interventions aimed at increasing the uptake of safe male circumcision services in such high-risk populations. Methods We conducted a cross-sectional study, employing mixed methods of data collection, at Kasenyi and Kigungu landing sites in April 2018. We included women aged 18–49 years, who had stayed at the landing sites for ≥3 months. We obtained qualitative data using focus group discussions (FGDs), and interviewer-administered semi-structured questionnaires for quantitative data. The tool captured demographic characteristics, community factors including cultural norms and beliefs, women’s experiences, and health facility-related factors. The dependent variable was derived from the response to the question: "Would you encourage your partner/husband to go for VMMC?", and used as a proxy for support of VMMC. We used modified Poisson regression to identify factors associated with women’s support for VMMC. Qualitative data were analysed using thematic content analysis. Results We enrolled 313 women with a mean age of 28 (SD±6.8) years. Of the 313 women, 230 (73.5%) supported VMMC. Belief that VMMC increases penile hygiene (Adjusted prevalence ratio [aPR]=1.9; CI: 1.8–3.2), performing VMMC for religious reasons (aPR=1.9; CI: 1.8–2.9), preference for a circumcised man (aPR=1.3; CI: 1.2–1.5), belief that vaginal fluids facilitate wound healing (aPR=1.9; CI: 1.3–2.7), and knowledge about when a man can resume sex (4 weeks) after circumcision (aPR=2.1; CI: 1.8–3.3) were associated with women’s support for VMMC. FGDs revealed that women were not adequately involved in VMMC activities for decision making. Conclusion The support for VMMC was high among women in the fishing communities. However, women perceived they were not involved in decision-making for VMMC and had several misconceptions, including a belief that vaginal fluids facilitate wound healing. The Ministry of Health and VMMC implementing partners should devise strategies to increase sensitization and involvement of women in VMMC decision-making without slowing service uptake.