The Circular Economy (CE) domain is increasingly leveraging ontologies to represent domain knowledge for data sharing and exchange. Several CE-related ontologies have been developed to model CE-specific knowledge for circular value networks. However, CE knowledge representation also relies heavily on existing ontologies from related domains, such as materials and manufacturing, due to the cross-industry nature of CE. Aligning CE-related ontologies is a key step toward enhancing interoperability and reusability. In this paper, we present alignment results and discussions on CE-related ontologies based on an extended ontology survey within the scope of the Onto-DESIDE project.