Purpose: To examine whether adverse childhood experiences (ACEs) are associated with breastfeeding behaviors. Methods: Women in three Kaiser Permanente Northern California medical centers were screened for ACEs during standard prenatal care (N = 926). Multivariable binary and multinomial logistic regression was used to test whether ACEs (count and type) were associated with early breastfeeding at the 2-week newborn pediatric visit and continued breastfeeding at the 2-month pediatric visit, adjusting for covariates. Results: Overall, 58.2% of women reported 0 ACEs, 19.2% reported 1 ACE, and 22.6% reported 2+ ACEs. Two weeks postpartum, 92.2% reported any breastfeeding (62.9% exclusive, 29.4% mixed breastfeeding/formula). Compared with women with 0 ACEs, those with 2+ ACEs had increased odds of any breastfeeding (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.3-5.6) and exclusive breastfeeding 2 weeks postpartum (OR = 3.0, 95% CI = 1.4-6.3). Among those who breastfed 2 weeks postpartum, 86.4% reported continued breastfeeding (57.5% exclusive, 28.9% mixed breastfeeding/formula) 2 months postpartum. ACE count was not associated with continued breastfeeding 2 months postpartum. Individual ACEs were not related to breastfeeding outcomes, with the exception that living with someone who went to jail or prison was associated with lower odds of continued breastfeeding 2 months postpartum. Conclusions: ACE count was associated with greater early breastfeeding, but not continued breastfeeding, among women screened for ACEs as part of standard prenatal care. Results reiterate the need to educate and assist all women to meet their breastfeeding goals, regardless of ACE score.