The Eastern Orthodox Church is officially known as the Orthodox Catholic Church. This term is used liturgically and officially and it of course reflects the understanding of “One, Holy, Catholic, Apostolic” in the Nicene Creed which we all recite in the liturgy.
But let me tell you, there are many Orthodox who do not like being called Catholic. There is frequently a campaign of vandalism to remove the term from the Wikipedia article. These poor people don’t realize how the term is used officially. They deny having anything to do with Roman Catholicism, even to the point of excising both words from the articles where they are backed up by reliable sources. It’s sad, really.