The objective of this study was to better understand US public awareness of maternal health benefits of breastfeeding. Data from the 2018 and 2021 SummerStyles surveys were analyzed to explore public belief in select maternal benefits of breastfeeding. As in 2018, in 2021 a low percentage of respondents believed that breastfeeding protects the mother against breast cancer (23.9%), high blood pressure (15.5%), or type 2 diabetes (15.4%), with male, older, and unmarried respondents less likely to believe in these protective effects. More public awareness of maternal benefits of breastfeeding might help increase demand for breastfeeding-supportive programs and policies.