Onopordum nezaketianum sp. nov. (Asteraceae: Cardueae) from the Central Anatolia region of Turkey is described based on morphological and palynological features. The new species is morphologically related to O. davisii Rech. f. and O. turcicum Danin, and is characterized by its capitula solitary or 2-4 on leafy 2-20 cm long peduncles, phyllaries 5-6 seriate, outer phyllaries sparsely arachnoid pubescent, ovate-lanceolate, flat or nearly reflexed; median phyllaries sparsely arachnoid pubescent, narrowly ovate-lanceolate, reflexed; inner phyllaries glabrous, linear-lanceolate, erect, flowers 20-25 mm; 4 corolla lobes equal, 4-5 mm long, and 5th lobe 6-7 mm long, pappus barbellate. Achenes 4.0-5.1 x 2.0-2.5 mm, grayish, obovate, deeply transverse rugose, with finely and irregularly undulate surface. Pollen grains of O. nezaketianum are trizonocolporate, oblate-spheroidal, and ornamentation microreticulate.