Despite the fact that English and Kazakh languages are rich in antonyms, which are universal phenomenon, in particular, the comparative study of antonyms in English and Kazakh languages is almost incomplete. In order to supplement it, the article provides an overview of the concept of antonyms in English and Kazakh languages, and reveals how often antonyms have been studied by other researchers. Conducted analysis of antonyms in English and Kazakh languages reveals the structural features of each language, their similarities and differences. Also, examples of antonyms as part the phraseological units with antonymous components were given, which were taken and analyzed from lexicographic dictionaries of the two studied languages, and based on the analysis of the dictionaries, it was determined how often different root and single-root antonyms occur. The practical significance of this work may affect its use in the teaching of the two languages under study, in comparative linguistics.Keywords: antonymy, lexis, structural analysis, single-root, different root, English language, Kazakh language.