The book of Revelation contains various literary devices, among which the oxymoron remains one of the least studied. This article is the first to explore this figure of speech in the book of Revelation and provides a precise definition of “oxymoron” as a unique combination of contradictory words whose literal meaning creates a paradoxical tension, enriching the textual meaning and provoking reflection. The study shows that many phrases previously called oxymora are in fact other literary forms, such as paradoxes or metaphorical contrasts, in which the tension results from theological or symbolic opposition rather than from direct lexical contradiction. The article argues that of the thirteen proposed examples, only the phrase “mixed unmixed” wine in Rev 14,10 corresponds to a classic oxymoron, which is used by John to intensify the image of God’s judgment. This article thus contributes to the study of the literary device of “oxymoron” in early Christian literature.