Background: In patients with severe knee joint diseases, especially osteoarthritis, total knee replacement (TKR) is a commonly used clinical procedure to alleviate pain and restore function. Although generally efficient in enhancing Health-Related Quality of Life (HRQoL), TKR outcomes vary greatly across individuals. The goal of this integrative review is to investigate the relationship between psychological profiles—including depression, anxiety, and stress—sociodemographic factors, and HRQoL outcomes among patients undergoing TKR. Methods: For papers published between 2015 and 2025, a comprehensive search of six electronic databases and manual reference checks was carried out. Nineteen pertinent studies were included, with a thematic synthesis focusing on depression, anxiety, stress, and key demographic variables. Results: This study steadily indicates that psychological profile—including depression, anxiety, and stress—negatively affects HRQoL after TKR. Demographic also substantially affect outcomes, repeatedly interrelating with psychological factors. Conclusion: Enhancing HRQoL after TKR involves combined, patient-centred approaches that consider both psychological health and Demographic diversity. It’s of immense importance to screen for mental health issues and the delivery of personalized interventions. More scientific investigations are required to guide plans of care that consider cultural backgrounds, mainly for individuals who are underserved.