Background: Low back pain (LBP) in older mothers is a prevalent and multifaceted condition influenced by a range of biopsychosocial factors. As the trend of late motherhood increases globally, it is essential to understand how LBP affects this population from a biopsychosocial perspective. Objective: This systematic review aims to examine the biopsychosocial determinants of LBP in older mothers by synthesizing findings from quantitative studies published between January 2010 and May 2024. Specifically, it explores the biological, psychological, and social factors contributing to LBP in this population and how it affects their daily lives and well-being. Methods: A comprehensive literature search was conducted across PubMed, PsychInfo, Web of Science, EMBASE, DARE, and the Cochrane Library. Studies were screened for eligibility based on predefined criteria. Five quantitative studies with a combined sample of 118,964 participants were included. The methodological quality was assessed, and data were extracted for analysis. Results: All five studies addressed biological aspects of LBP, including pelvic girdle pain, hemorrhoids, and varicose veins. Three studies also explored psychological factors such as depression and stress. Two studies incorporated social dimensions, including inadequate support systems, occupational burdens, and healthcare access barriers. Age and parity were consistently reported as exacerbating physical and psychological symptoms. Conclusions: This review highlights the importance of considering biopsychosocial factors when managing LBP in older mothers. Tailored interventions, such as exercise programs, family support, and workplace accommodations, are essential for improving outcomes. Further research using longitudinal studies is needed to explore these factors in greater depth.