The article tackles the problem of interpreting the phenomenon of boredom in A. Schopenhauer’s and M. Heidegger’s works. This problem has not been previously investigated by domestic and foreign researchers. Analysing A. Schopenhauer’s views on the nature of boredom in the context of his metaphysical conception of will as a “thing in itself” and M. Heidegger’s interpretation of boredom as a fundamental mood, the researcher identifies evident similarities as well as historical and philosophical parallels in their interpretations.