Objective: Pregnancy is often described as a pivotal life stage for women, where regular contact with health professionals may play an important role in lifestyle awareness. This study explored the knowledge, practices, and beliefs of health professionals and pregnant women regarding physical activity and weight management during the antenatal period. Methods: A qualitative study was undertaken in southeastern Australia using individual interviews. Recruitment sought women of gestation >12 weeks, experiencing an uncomplicated pregnancy ( n = 6), and antenatal health professionals including midwives ( n = 4) and an obstetrician ( n = 1). Data were analysed using Interpretive Phenomenological Analysis. Results: Three major themes emerged: (1) women rely on multiple sources of pregnancy-related healthy lifestyle information; (2) discussions around healthy lifestyle behaviours are low priority and often inconsistent; and (3) lifestyle-related topics perceived as sensitive make some conversations and actions difficult. Conclusions: Pregnant women expressed gaps in lifestyle-related knowledge and education being provided by health professionals. In turn, health professionals expressed difficulty discussing sensitive topics such as weight with pregnant women and had limited knowledge of pregnancy-specific physical activity guidelines. The themes generated by this study may form the foundation for further research to inform clinical policy and practice regarding advice in antenatal care.