Filyos, also known as Hisarönü, is a coastal town located in the Çaycuma District of the Zonguldak Province in Turkey. Situated within the Black Sea Region, the town is positioned at the mouth of the Filyos River. It is located approximately 18 kilometres from Çaycuma and 27 kilometres from Zonguldak.
The settlement was officially declared a seat of township in 1954. Historically, the town was known as Tieion, a name referring to its founder. The primary economic activity in Filyos is the firebrick industry, though tourism is also considered a promising sector for the area.