Tripleurospermum insularum Inceer & Hayirhoglu-Ayaz sp. nova (Asteraceae, Anthemideae) is described and illustrated. It grows in open places and on rocky slopes in Gokceada, one of the Aegean Islands. The chromosome number is 2n = 2x = 18. The diagnostic morphological characters that distinguish it from morphologically similar species are discussed and a conservation status is suggested.