Yıldızköy is a village in Şefaatli District, in Yozgat Province, Türkiye. Yıldızköy lies at 1,101 m above sea level, 6.6 km from the Anatolian plateau mountains. It has 270 inhabitants. The nearest city is Yozgat, 26 km to the north. Among the landmarks around are Hattusa (50 km), Pteria (29 km) and Yazılıkaya (51 km).

Also written Seydiyar.