Digital Circular Economy and Industry 5.0 have been two significant research attractions in the last years, due to the evolution of their predecessors into advanced technologies. Circular Economy (CE) has progressed into a sustainable digital approach, capable to be implemented into different scenarios. Industry 5.0 has turned from a fully automated application field into a balanced technological combination of A.I. and M.L. with the involvement of human factor, and promising enabler of Digital CE. As a result, a growing number of Digital CE models are introduced into the academic community. In this work, we collect and examine the latest research and application trends of Digital CE models, by studying their sustainable features, requirements, applications, and architectures.