The article examines connotation and its role in metaphorization in the Altai and Mongolian languages. The relevance of the topic lies in the lack of study of connotation in both the Altai and Mongolian languages from a comparative perspective. The methods used include surveys of informants, descriptive method, synchronic method, and comparative method. The novelty of the research consists in the introduction of new lexical material in comparison with the Mongolian language and in determining the national-cultural specifics of the analyzed units within the framework of the Altai and Mongolian languages. The study has shown that the figurative component, which is a generalized, sensory-visual image of an object denoted by a sign, is closely related to connotation. In the Altai and Mongolian languages, depending on the dominant connotation, four main groups of expressive words are distinguished: 1) purely expressive words, e.g., Alt. jaltanbas/korkybas, Mong. zürkhteĭ/aimshiggüi/erelkheg – 'daredevil' – with an emotion of admiration and a positive assessment of a very brave person; 2) words carrying emotional-expressive coloring, e.g., Alt. kӧӧrkiĭek/jalakai, Mong. zürkhnii/khairtai – 'sweetheart'; 3) stylistically expressive words, e.g., Alt. keber/ser/yes, Mong. niguur/tsarai – 'face'; 4) 'depictive' words, devoid of the original nominative basis, e.g., Alt. soksoo, Mong. munag khün – 'blockhead'. The researchers conclude that besides the four already identified groups of expressive words in the Altai and Mongolian languages, there is another, most extensive group consisting of figurative-expressive words, also known as metaphorical nominations, and it is these that become the subject of our study. The studied material can be applied in compiling dialectal, phraseological, and linguocultural dictionaries of the Altai and Mongolian languages, which determines the practical value of this article.