Alaçay is a village in Devrekani District, in Kastamonu Province, Türkiye. Alaçay lies at 1,197 m above sea level, 2.2 km from the Küre mountains. It has 104 inhabitants. The nearest city is Kastamonu, 42 km to the southwest. Among the landmarks around are Kulaksızlar Dam (11.4 km), Pompeiopolis (25 km) and Mahmut Bey Mosque (38 km).