The relevance of the study is due to the lack of attention on the part of international and national legislation to such an object of intellectual property as well-known trademarks, in particular, to the regulation of their legal defence, and therefore this issue requires research and coverage in scientific circles. The purpose of the study is to investigate the difference between legal protection and legal defence of well-known trademarks in Ukraine. General scientific methods of knowledge (generalisation, formal-logical, synthesis, axiomatic) and special-legal methods (formal-legal, logical-legal, comparative-legal) were used to examine this problem. The paper considers the key features of well-known brands. By analysing the Ukrainian regulatory framework, it is established that the legal protection of well-known trademarks in Ukraine complies with the norms of international legislation, namely the provisions of Article 6 bis of the Paris Convention. A detailed analysis of the concepts of protection and defence is conducted and applied to the object of the study. It was established that the peculiarity of well-known trademarks is that they acquire the status of a protected object of intellectual property rights not from the moment of state registration but from the time of their recognition in the country, which means acquiring the status of being famous. The practical value of the study is that the results obtained can be used to improve the procedure for recognising trademarks as well-known, namely, to justify the possibility of choosing the appropriate course of action: by applying to the appeals chamber or applying to the court.