Antibiotic use and misuse are common in pregnant women and young children. Few studies have assessed real-world discussions of antibiotics in these populations. Using social media posts of pregnant women and parents, our goal was to identify key themes about facilitators and barriers to appropriate antibiotic usage. A purposive sample of public posts and comments relevant to antibiotic use was collected from the BabyCenter United States social media site. Using a directed content analysis, themes related to facilitators and barriers to appropriate antibiotic use were identified. Seven hundred and twenty-six posts and 5227 comments were analysed. Themes centred around individual factors, interpersonal factors, and structural factors. Individual factors included knowledge and beliefs. Though misinformation was present, most parents were aware of appropriate antibiotic usage and perceived antibiotics as safe and effective. Some hesitance around using antibiotics led to recommendations for home remedies or over-the-counter treatments. Interpersonal factors focused on a lack of available offline peer support, the expertise of providers, as well as a potential lack of attention from those providers. Structural factors, including access to care, also impacted parents' antibiotic use and misuse. Though most parents demonstrated appropriate knowledge about antibiotics and a willingness to follow guidelines, negative experiences with their providers, a lack of support from peers, and structural factors presented as potential barriers to appropriate antibiotic use. Implementing avenues for peer support for parents, allowing more time for providers to address parents' concerns, and improving access to providers could improve appropriate antibiotic use in parents.