Sauna bathing is a culturally significant practice in Nordic countries and is increasingly recogniced as a multidimensional health-promoting behavior. Although its physiological benefits are well-documented, less is known why people engage in sauna bathing and how they perceive its contribution to health and well-being. To investigate why Swedish women and men engage in sauna bathing and to describe their perceptions of sauna bathing as a health-promoting practice. A descriptive cross-sectional study was conducted using an online questionnaire completed by 588 regular sauna bathers (384 women and 204 men). The questionnaire included closed-ended items on health and sauna habits and open-ended questions exploring motivations for sauna bathing. Qualitative data were analysed using inductive thematic analysis, and quantitative data were analysed using descriptive and analytic statistics. Thematic analysis generated a conceptual model of sauna bathing as a health-promoting practice comprising four interconnected themes: mental recovery, social togetherness, purification and physical health. Mental recovery was the prominent motivation among women, whereas social togetherness ranked highest among men. Participants described sauna bathing as promoting relaxation, reflection, social connection, physical recovery, and a sense of cleanliness and renewal. Women reported significantly better perceived sleep quality and reduced perceived bodily pain following sauna bathing, whereas no corresponding significant changes were observed by men. Sauna bathing was perceived as a multidimensional health-promoting practice integrating psychological, social, cultural, and physical dimensions of health. The findings provide a conceptual understanding of why people engage in sauna bathing and support its potential role as a person-centered health promotion strategy. Prospective studies are needed to confirm these self-reported findings.