Internationally, intimate partner violence (IPV) cohorts have demonstrated associations with depression and anxiety. However, this association has not yet been described in a UK population, nor has the association with serious mental illness (SMI). To explore the relationship between IPV exposure and mental illness in a UK population. We designed a retrospective cohort study whereby we matched 18 547 women exposed to IPV to 74 188 unexposed women. Outcomes of interest (anxiety, depression and SMI) were identified through clinical codes. At baseline, 9174 (49.5%) women in the exposed group had some form of mental illness compared with 17 768 (24.0%) in the unexposed group, described as an adjusted odds ratio of 2.62 (95% CI 2.52-2.72). Excluding those with mental illness at baseline, 1254 exposed women (incidence rate 46.62 per 1000 person-years) went on to present with any type of mental illness compared with 3119 unexposed women (incidence rate 14.93 per 1000 person-years), with an aIRR of 2.77 (95% CI 2.58-2.97). Anxiety (aIRR 1.99, 95% CI 1.80-2.20), depression (aIRR 3.05, 95% CI 2.81-3.31) and SMI (aIRR 3.08, 95% CI 2.19-4.32) were all associated with exposure to IPV. IPV remains a significant public health issue in the UK. We have demonstrated the significant recorded mental health burden associated with IPV in primary care, at both baseline and following exposure. Clinicians must be aware of this association to reduce mental illness diagnostic delay and improve management of psychological outcomes in this group of patients.