The topic of this dissertation is the onomastic research of Lika’s historical and contemporary toponymy. This refers to the corpus of 4409 toponyms, mainly oikonyms, hydronyms, oronyms and speleonyms, which were excerpted from historical and contemporary maps and historical and other available sources. Part of the toponymy database was collected through field research, and part was collected through subsequent targeted verification in the field – for example, all inhabitant names and adjectival forms of place names and a large part of hydronyms. Toponyms were analysed at a motivational, structural and linguistic layering level, each toponym separately within the scope of a toponym group. The analysis included the description of Lika’s historical, geographical, linguistic and demographic peculiarities, as well as population and settlement formation processes from Pre-Slavic to contemporary age. The processing of historical and contemporary toponyms included the description and analysis of all available relevant linguistic and extra linguistic elements, which influenced the formation of names in order to clarify their aetiology and historical continuity. The comprehensive analysis of processed toponym groups has allowed the separation of onomastic characteristics of historical and contemporary toponymy of Lika. Special attention was dedicated to the study of name continuity, the transmission of a determined name to other geographical references and the analysis of linguistic and toponymy layering in order to identify the characteristics of each toponymy group and Lika’s toponymy as a whole. Therefore, level descriptions especially of historical, geographical, archaeological, ethnological, and demographical and other extra linguistic data were adjusted to the requirements of onomastic description. Considering the tumultuous history of Lika, sources that allow the examination of administrative norms regarding Lika’s toponymy as well as the description of naming and renaming, especially of Lika’s settlements, mountain tops and caves have been examined in detail. This paper is the first systematic description of Lika’s historical and contemporary toponymy, and it includes all available knowledge of Lika’s toponymy so far. The scope and processing level of the defined topic in the dissertation allows the examination of the historical development, structure and typology of geographical names in the area of Lika.