Empirical evidence on COVID-19 vaccination and lactation-related outcomes remains limited. We used electronic health record data from four US healthcare systems to assess the association between COVID-19 vaccination and milk feeding outcomes. We included pregnant persons with a live birth between December 2020-September 2022 with infant linkage. We assessed two COVID-19 vaccination exposure windows-during pregnancy ( ≥ 20 weeks gestation vs no vaccination during pregnancy) or postpartum (<7 months after delivery vs none). We estimated adjusted prevalence ratios (aPR) for COVID-19 vaccination during pregnancy and human milk feeding non-initiation and discontinuation, and we estimated adjusted hazard ratios (aHR) for postpartum COVID-19 vaccination and human milk feeding discontinuation. In the study population used to assess pregnancy exposure(n = 10 757), 4.2% of birthing parents did not initiate human milk feeding. Non-initiation did not differ by vaccination during pregnancy (aPR = 0.99, 95% CI: 0.98-1.01). Antenatal vaccination was not associated with human milk feeding discontinuation at two and six months after delivery. In the study population used to assess postpartum exposure (n = 17 161), human milk feeding discontinuation did not differ by postpartum vaccination (aHR = 1.03, 95% CI: 0.95-1.11). COVID-19 vaccination in pregnancy and postpartum were not associated with human milk feeding discontinuation.