Abstract Background Intimate partner violence (IPV) is a global public health and human rights issue that affects millions of women and girls. While disaggregated national statistics are crucial to assess inequalities, little evidence exists on inequalities in exposure to violence against adolescents and young women (AYW). The aim of this study was to determine inequalities in physical or sexual IPV against AYW and beliefs about gender based violence (GBV) in sub-Saharan Africa (SSA). Methods We used data from the most recent Demographic and Health Surveys (DHS) conducted in 27 countries in SSA. Only data from surveys conducted after 2010 were included. Our analysis focused on married or cohabiting AYW aged 15–24 years and compared inequalities in physical or sexual IPV by place of residence, education and wealth. We also examined IPV variations by AYW’s beliefs about GBV and the association of country characteristics such as gender inequality with IPV prevalence. Results The proportion of AYW reporting IPV in the year before the survey ranged from 6.5% in Comoros to 43.3% in Gabon, with a median of 25.2%. Overall, reported IPV levels were higher in countries in the Central Africa region than other sub-regions. Although the prevalence of IPV varied by place of residence, education and wealth, there was no clear pattern of inequalities. In many countries with high prevalence of IPV, a higher proportion of AYW from rural areas, with lower education and from the poorest wealth quintile reported IPV. In almost all countries, a greater proportion of AYW who approved wife beating for any reason reported IPV compared to their counterparts who disapproved wife beating. Reporting of IPV was weakly correlated with the Gender Inequality Index and other societal level variables but was moderately positively correlated with adult alcohol consumption (r = 0.48) and negative attitudes towards GBV (r = 0.38). Conclusion IPV is pervasive among AYW, with substantial variation across and within countries reflecting the role of contextual and structural factors in shaping the vulnerability to IPV. The lack of consistent patterns of inequalities by the stratifiers within countries shows that IPV against women and girls cuts across socio-economic boundaries suggesting the need for comprehensive and multi-sectoral approaches to preventing and responding to IPV.