During the past decade, research on the link between childhood emotional maltreatment and adulthood romantic relationship well-being has been accumulating, but there still lacks a systematic, quantitative evaluation of existing research. This three-level, meta-analysis aimed to fill this gap. Reports were included if they examined the link between early emotional maltreatment and adulthood romantic relationship well-being, presented statistics needed to calculate at least one bivariate effect size, written in English, and published/written before January 1, 2020. We retrieved 201 effect sizes from 23 reports. Early emotional maltreatment (aggregated across forms) was negatively (yet modestly) associated with later romantic relationship well-being (aggregated across dimensions; r = −.143, 95% confidence interval [−.173, −.114], p < .001). This association did not vary as a function of maltreatment form but differed across relationship well-being dimensions, such that the effect was stronger for the negative than for the positive relationship outcomes. We also found that (a) the actor effect was larger than the partner effect, (b) the effect was stronger in studies using Childhood Trauma Questionnaire (CTQ) than in studies not using CTQ, (c) whether using established measures of relationship well-being did not alter the effect, (d) the absolute magnitude of effect was negatively associated with methodological rigor of effect, and (e) the effect did not vary as functions of publication type, whether the sample was a college student sample, or union status, and was not related to the mean of union duration. Last, the limitations of existing research, avenues for future inquiries, and implications for practice were noted.