The blaze started at around 0027GMT in the restaurant area of the hotel, quickly engulfing the building, according to Bolu Governor Abdulaziz Aydın.
Emergency teams from neighboring cities, including firefighters, disaster response units, and medical teams supported by helicopters were dispatched to the scene.
Authorities evacuated around 230 guests from the hotel as firefighting efforts continued.
Investigation into the cause of the fire was initiated.
Kartalkaya in the province of Bolu is one of Türkiye's premier winter tourism destinations, attracting thousands of visitors during the ski season. The resort lies around 295 kilometers (183 miles) east of Istanbul.
