Xynomizithra or xynomyzithra (Greek ξυνομυζήθρα) is a traditional unpasteurized Greek cheese, a sour variant of mizithra. It is made from sheep's and/or goat's whey with the addition of milk. The cheese is soft, snow-white, creamy in texture, and granular. It is made in various sizes and usually shaped like a truncated cone.
Xynomyzithra Kritis 'xynomizithra of Crete' is a European protected designation of origin.