Introduction Intimate Partner Violence (IPV) is linked to low engagement with HIV management services and adverse clinical outcomes, including poor ART adherence. In sub-Saharan Africa, studies on pregnant/postpartum women and transactional sex workers have produced divergent evidence regarding IPV’s association with poor ART adherence. We investigate this association among a broad group of women. Methods We sampled 408 HIV-positive women receiving free ART from different types of HIV clinics at government health facilities, assessing for IPV exposure by a current partner, ART adherence rate, and other factors that affect ART adherence (e.g. education, disclosure). ART adherence rates were measured using the Visual Analogue Scale (VAS); responses were dichotomised at a ≥95% cut-off. Multiple logistic regression models assessed the association between the independent variables and ART adherence. Results The participants’ mean age was 38.6 (range: 18–69 years). The majority had ever attended school (94%, n = 382), were in monogamous marriages (70%, n = 282), and had disclosed status to partners (94%, n = 380). Overall, 60% (n = 242) reported optimal ART adherence (≥ 95%) in the previous 30 days. The prevalence of IPV by the current partner was 76% (CI95 = 72–80%). Experiencing physical IPV (AOR 0.57, CI95: 0.34–0.94, p = .028), sexual IPV (AOR 0.50, CI95: 0.31–0.82, p = .005), or controlling behaviour (AOR 0.56, CI95: 0.34–0.94, p = .027) reduced the odds of achieving optimal adherence, while a higher education level and having an HIV-positive partner increased the odds. Conclusion IPV is common and is associated with suboptimal ART adherence rates among a broad group of HIV-positive women. ART programs could consider incorporating basic IPV interventions into regular clinic services to identify, monitor and support exposed women, as they might be at risk of poor ART adherence. Still, there is need for more research on how IPV affects ART adherence.