This study aimed to investigate the relationships among employees' perceptions of Total Quality Management (TQM) and Talent Management (TM) practices within their organisations, as well as the impact on Sustainability Performance (SP). The research used survey data from businesses in Istanbul, Yalova, and Kocaeli provinces. A convenience sampling method was employed, and the study utilised data from 339 managers and employees in the manufacturing sector. The data analysis was conducted using least square structural equation analysis. The study’s findings revealed that an increase in the level of TQM application is associated with higher levels of TM application and improved SP in enterprises. Furthermore, it was observed that the positive impact of the TQM level increase extends to both TM and SP through a quadratic effect, in addition to its direct influence. The study demonstrated that increasing TM application significantly enhances SP, and an elevated TQM level further amplifies this relationship. Additionally, when the companies were classified based on size, it was found that the positive effect of an increased TQM implementation level on SP is significantly more pronounced in medium-sized companies compared to small and large companies. This trend was also observed in the quadratic effect analysis.