Although several studies have shown that childhood maltreatment (CM) is associated with a host of negative consequences including romantic relationship difficulties for victims in adulthood, most overlooked the potential effects on the romantic partner. This systematic review and meta-analysis aims to comprehensively synthesize the literature on the association between a person’s CM and their partner’s individual and couple outcomes. We searched PubMed, PsycNET, Medline, CINAHL, and Eric using search strings related to CM and partner. We identified 3,238 articles after removal of duplicates; 28 studies met the inclusion criteria and relied on independent sample. The studies reported associations between a person’s CM and a wide breadth of partner’s negative couple outcomes (e.g., communication, sexuality) as well as intra-individual psychological difficulties (e.g., psychological distress, emotion, and stress reactivity). Meta-analytic results showed significant, but trivial to small associations between a person’s CM and their partner’s lower relationship satisfaction ( r = −.09, 95% CI [−.14, −.04]), higher intimate partner violence ( r = .08, [.05, .12]), and higher psychological distress ( r = .11, [.06, .16]). These associations were similar for women and men and did not differ as a function of sample’s mean age, proportion of cultural diversity, and publication year. These findings suggest that a person’s CM is related to their partner’s outcomes including to the partner’s intra-individual outcomes. Prevention and intervention strategies should acknowledge that a person’s CM may also affect their romantic partner, considering the couple as a reciprocal system, and offer victims’ romantic partners specific services.