The aim of this study is to investigate the validity of the environmental Kuznets curve hypothesis in the EU-24 member countries within the circular economy framework and to examine the validity of the sustainable waste management hypothesis. For this purpose, two different models are established to examine the validity of the hypotheses for the 2000-2020 period. The first model examines the existence of a parabolic relationship between real national income and environmental degradation and waste management's effect on environmental degradation. The second model investigates the possible parabolic relationship between real national income and waste management. The study used cross-section dependence, homogeneity test, CIPS unit root test, Pooled Mean Group-, autoregressive Distributed Lag (PMG-ARDL) estimation techniques and Dumitrescu-Hurlin causality tests. In the first model findings, it is revealed that energy consumption and population have a positive effect on CO2 emissions. However, the effect of waste recycling rates on environmental degradation is negative and statistically significant. In addition, an inverted U-shaped relationship between economic growth and emission levels has been proven valid; thus, it has been concluded that the Environmental Kuznets curve is valid in EU-24 member countries. Within the scope of the second model, we can say that waste recycling rates decrease in the early stages of economic growth in the long term, while waste recycling rates increase in the later stages of economic growth. This finding shows the validity of a U-shaped relationship between economic growth and waste management. Therefore, the validity of the Sustainable Waste Management hypothesis in EU-24 member countries has been proven by the findings of the second model. In addition, it is concluded that the effect of the increase in population and energy consumption on the amount of recycling was statistically significant and positive.