ObjectiveThe association between intimate partner violence (IPV) and breastfeeding is unclear. We conducted a systematic review to summarise the evidence of breastfeeding outcomes following exposure to IPV.DesignSystematic review.MethodsWe searched for published studies without study design or language restrictions (up to July 2019) in the following databases: PubMed, Embase, SCOPUS and The Global Health Library. Studies assessing various breastfeeding outcomes (initiation, duration and exclusive breastfeeding) in women exposed to IPV in any form (physical, psychological or sexual) and at any stage (1 year pre-pregnancy, during or post-pregnancy) were included. Two authors independently selected the studies and conducted the quality appraisal by use of the Newcastle–Ottawa Scale. Results were summarised taking precision and quality into account.ResultsA total of 16 studies (participants n=414 393) were included and they adjusted for a total of 48 different confounders. The majority of studies were cross-sectional (n=11) and most studies were judged to be fair/low quality. Four out of seven studies found that IPV exposure shortened breastfeeding duration (adjusted ORs/aORs=0.22 (95% CI: 0.05–0.85), 1.18 (95% CI: 1.01–1.37), 5.92 (95% CI: 1.72–27.98), 1.28 (95% CI: 1.18–1.39)). Further, 5/10 studies found that IPV led to early termination of exclusive breastfeeding (aORs=1.53 (95% CI: 1.01–23.1), 0.83 (95% CI: 0.71–0.96), 1.35 (95% CI: 1.07–1.71), 0.17 (95% CI: 0.07–0.4), 1839 (95% CI: 1.61–2911)) and 2/6 studies found that IPV significantly reduced breastfeeding initiation (aORs=2.00 (95% CI: 1.2–3.3), 0.81 (95% CI: 0.7–0.93)).ConclusionIPV exposure appears to associate negatively with some breastfeeding outcomes. Individual patient data meta-analysis is required to quantify the magnitude of the association for specific IPV-outcome combinations. More high-quality studies and definition of core confounders are warranted.PROSPERO registration numberCRD42019129353.