In this paper, a new Centaurea L. (Asteraceae) species from Turkey is described and illustrated. Centaurea sakariyaensis Uysal & Dural grows on rocky crevices in Sakarya province in north-western Anatolia. It belongs to C. sect. Centaurea L. and taxonomically its closest relative is C. wiedemanniana. Diagnostic morphological characters from a very similar taxon are provided, and a key from flora of Turkey is modified that includes related species of sect. Centaurea. The geographical distribution of the new species and species of other related taxa of the same section are mapped. The chromosome number of C. sakariyaensis, 2n = 18, counted in root tips, is also reported and illustrated.