Breastfeeding promotes health and well-being for both mother and infant. A variety of environmental and individual factors, including psychological ones, affect infant feeding practices. The purpose of this study was to determine the feasibility and effectiveness of a single-session Motivational Interviewing (MI) intervention delivered during the third trimester of pregnancy for enhancing breastfeeding outcomes. The Theory of Planned Behavior provided a theoretical framework for the intervention and outcome measures. The sample consisted of predominantly rural participants living in the North Central Appalachian region. Women were recruited through social media, local clinics, and word of mouth. Participants (N = 81) completed one in-person session during the third trimester of pregnancy and one follow-up phone call at one month postpartum. All participants were randomly assigned to either the MI intervention or a psychoeducation intervention focused on infant developmental milestones. Prepost intervention outcome measures included infant feeding intentions, perceived behavioral control of breastfeeding, perceived importance of breastfeeding, infant feeding knowledge, breastfeeding attitudes and subjective norms, and knowledge of infant development. At one month postpartum, participants completed a phone interview which assessed breastfeeding initiation and current breastfeeding status. Directly following the intervention, there was a significant effect of the MI intervention on increasing breastfeeding attitudes among primiparous women only (p < .05). In addition, at one month postpartum, women in the MI group were more likely to report any current breastfeeding than women in the psychoeducation group, χ² (1, N = 79) = 4.30, p = 0.040, Φ = .233. There were no significant between-group differences on intentions, perceived behavioral control, perceived importance, subjective norms, infant feeding knowledge, knowledge of infant development, likelihood of exclusive breastfeeding at one month postpartum, total proportion of feedings that were breast milk at one month postpartum, or plans for continued breastfeeding at one month postpartum. Results of this study support the feasibility of a single-session, prenatal MI intervention. Preliminary findings demonstrate MI's effectiveness in increasing the likelihood of any breastfeeding at one month postpartum, and in enhancing breastfeeding attitudes among primiparous women. Future work in this area may benefit from implementing electronic communication to reinforce messages of MI interventions. From a public health perspective, future work in this area should target populations facing breastfeeding inequities and disparities. This trial was registered on clinicaltrials.gov NCT03033459 This project would not have been possible without the 81 women who invited me into their hearts and (quite literally) their homes to participate in this project. It was a joy and privilege to know each of them. I owe countless thanks to my mentor and dissertation chair, Dr. Dan McNeil, whom...