The article exposes the conception of a dictionary reflecting the system of proper names of a traditional culture bearer. The dictionary is supposed to focus upon the onomasticon of a dialect speaker retrieved from the oral discourse of one person; it aims to treat all types of proper names of the respective idiolexicon and to reflect their diverse functions in the speaker’s communication. The dictionary in question is a part of the collection of dictionaries created by the Tomsk Linguistic School and oriented to a comprehensive study of the language of one particular dialect speaker. Methodologically, the Idiolect Onomasticon of a Siberian Old-Timer follows the published Comprehensive Dictionary of a Dialect Language Personality, the basic dictionary of the informant’s appellative lexicon, with some transformations induced by the specificity of names as an object of lexicographic description. The author discusses the sources of the Onomasticon, its general structure, the peculiarities of the presentation of proper names in the three sections of the dictionary dealing with personal names, place names and other types of names. The article contains examples of entries from all the three sections. The author also outlines possible applications of the dictionary to idiolect studies, onomastics, dialectology, namely, to the study of the structure and the meaning of lexical units, their functioning, the specificity of a dialect speaker’s metalinguistic reflection and linguistic worldview.