Maternal psychological well-being is a critical determinant of health outcomes for mothers and their children, encompassing emotional, mental, and social dimensions of health during pregnancy, childbirth, and the postpartum period. This chapter explores the multifaceted concept of maternal psychological well-being, examining its biological, psychological, social, and cultural determinants. Hormonal fluctuations, physical health, pre-existing mental health conditions, self-efficacy, and social support systems all play pivotal roles in shaping maternal mental health. The consequences of poor psychological well-being are far-reaching, impacting mothers’ physical recovery, children’s behavioral and cognitive development, and family dynamics. Interventions, including cognitive-behavioral therapy, mindfulness-based approaches, peer support programs, and policy measures such as maternity leave and integrated mental health care, are effective in promoting maternal mental health. Drawing on global trends and evidence from Ethiopia, this chapter emphasizes the need for a multidisciplinary approach to address maternal psychological well-being, recognizing its centrality to maternal and child health outcomes.