Research about the association between early marriage and intimate partner violence (IPV) in low-income countries has yielded conflicting evidence. The aim of this study was to describe the prevalence of and associations between early marriage, and IPV among adolescents and young adults in Viet Nam. Secondary analysis of data from the national Survey Assessment of Viet Namese Youth–Round II (SAVY-II) conducted in 2009-2010, which assessed a representative cohort of people aged 14 to 25 years recruited via a systematic household survey was undertaken. Prevalence was established using descriptive statistics. The association between early marriage and IPV was examined using multiple logistic regressions, adjusting for potential risk factors. Of 10,044 participants, 1,701 had ever married and were included in analyses. Early marriage (before age 18), and experiences of verbal, physical, or sexual IPV were more common among females than males. More young married men than women reported experiences of controlling behaviors by their partners. Early marriage, being illiterate, and exposure to sexual abuse were associated with experience of IPV among young females, but not among young males. Poverty and exposure to family violence was associated with IPV in both sexes. Addressing early marriage, low educational opportunities for girls, childhood sexual abuse, family violence, and poverty should be considered in strategies to reduce IPV in Viet Nam.