Introduction. On February 23, 2023, Professor of the Mari State University, prominent and talented Mari linguist Anatoly Nikolaevich Kuklin would have turned 75 years old. His creative activity is connected with the study of theoretical problems of regional toponomastics, contrastive linguistics, controversial issues of ethnogenesis and ethnic history of the peoples of the Uralic language community. The purpose of the article is to present the scientific and pedagogical activity of Anatoly Nikolaevich Kuklin, Doctor of Philology, Professor of the Mari State University (23.02.1948 ‒ 14.05.2016) and describe his contribution to the practice of teaching Mari toponymy in the framework of linguistic local lore. Anatoly Nikolaevich Kuklin was one of the outstanding scientists of the Republic of Mari El, a Finno-Ugric scholar and educator, the author of more than 400 scientific papers in the field of phonetics, general linguistics, toponomastics. Of particular note is the contribution of A. N. Kuklin to the study of linguistic local studies in the framework of the theory of toponomastics. The main directions of the scientist’s activity are: research in the field of onomastics, establishment of kinship relations of words in toponymy, explanation of the origin of toponyms; interpretation of the processes of mutual influence and mutual enrichment of languages of the Ural-Volga historical and ethnographic region; development of educational and methodological manuals for educational institutions of the Republic of Mari El. A. N. Kuklin was a Professor (1999), High Achiever of Public Education (1991), Honored Scientist of the Republic of Mari El (1998), Honorary Worker of Higher Professional Education of the Russian Federation (2006), Honored Worker of Science and Education (2014), founder of the scientific school “Mari Onomatology”. Conclusion. A. N. Kuklin considered toponymy to be the most important element of the regional educational system, a means of preserving national memory, studying the historical and cultural heritage of his native land, reflected in geographical onyms.