Intimate partner violence (IPV) profoundly impacts mental health, yet systematic syntheses of recent evidence remain limited, particularly in diverse global contexts. This systematic literature review examines the bidirectional relationship between IPV and mental illness, identifying prevalence, risk factors, common disorders, interventions, and support systems for victims. Following PRISMA guidelines, we searched PubMed and Scopus for primary research published in English between 2012 and 2024. From 759 records, 34 eligible studies were screened using predefined inclusion and exclusion criteria. Data were extracted and analyzed using a thematic analysis approach to identify recurring patterns and key themes. IPV prevalence is high globally, surging during crises like COVID-19 lockdowns, with strong links to depression, anxiety, PTSD, postpartum depression, and substance use. Key risk factors include low socioeconomic status, parental violence, substance abuse, and gender disparities (women disproportionately affected). Interventions like trauma-informed CBT show promise, but barriers to help-seeking persist. Studies skew toward USA/UK; gaps exist in Asia/Africa, male/LGBTQ+ populations, and intervention efficacy. IPV drives significant mental health burdens, underscoring needs for culturally tailored supports and expanded research. Policymakers should prioritize prevention, screening, and accessible interventions to mitigate long-term impacts.