Being overweight or obese increases the risk of pregnancy complications, including prolonged time to pregnancy, infertility due to hormonal disorders, early miscarriage, gestational diabetes, and pre-eclampsia. In addition, children exposed to maternal overweight or obesity in utero have a 2-3 times higher risk of childhood obesity and type 2 diabetes compared to children of women with a BMI of 25 kg/m2. This study aimed to synthesize experiences of improving pre-pregnancy weight status in overweight or obese women using a qualitative meta-synthesis method. Three studies on experiences of improving pre-pregnancy weight status in overweight or obese women were searched and analyzed in eight Korean and English databases. The selected studies were synthesized using the meta-synthesis proposed by Sandelowski and Barroso (2003). Through meta-synthesis, four themes were derived: “Process of forming a subjective health identity,” “Construct meaning through social interaction,” “Intersection of environmental constraints and resources,” and “Mechanics of practice of goal-oriented self-regulation.” Women cited lack of dietary knowledge, conflicting priorities, and the cost of a healthy lifestyle as important obstacles to achieving and maintaining weight loss. Overweight or obese women were in a situation where they needed to improve their pre-pregnancy weight status for a successful pregnancy, but they had difficulty doing so due to lack of partner support, negative mental health status, lack of awareness of weight-related pregnancy complications, and lack of nutrition knowledge. This study provide a deeper understanding of the experiences of overweight or obese women in improving their pre-pregnancy weight status, which will help develop diverse and effective support strategies, including interventions for partners.