As it's known, tradition of classifying sciences had started with Aristotle in Ancient Greek, who had classified sciences in his philosophical works as theoretical, practical and poetic and his views had been continued and developed by neoplatonic philosophers and medieval Muslim thinkers. Especially, the medieval Muslim thinkers did not just received this classification, but also improved it to discover new scientific fields. Among medieval Muslim thinkers, attempts to classify the sciences began as early as the third/ninth century with C?bir ibn Hayy?n and was developed thereafter by al-Khw?rizm?, al-Kind?, Abû Nasr al-F?r?b?, Avicenna, al-Ghazal? etc.. Muslim thinkers’ classification of science is important in, showing the topics, contents, methods, values and hierarchical relations of sciences with each other. Also it expresses understanding of the thinkers general epistemology and epistemology of science, point of view, and handling the topics. This article is about İbn Abd al-Barr’s classification of sciences within the framework of his epistemological foundations. For this reason, in this study, we aim to analyse Ibn Abd al-Barr’s epistemology and classification of sciences and show their relationship with each other and compare his classification of sciences other Muslim thinkers’ classifications.