Abstract: Per- and polyfluoroalkyl substances (PFAS) in food packaging paper are strictly regulated due to their high toxicity and migration risks. This study aims to systematically assess the fluoride content levels in food packaging paper and analyze their possible sources in raw and auxiliary materials. The total fluorine (TF), total organic fluorine (TOF), and extractable organic fluorine (EOF) in 26 commercial paper packaging materials and 65 raw and auxiliary materials for papermaking were quantitatively analyzed using the oxygen bomb combustion-ion selective electrode method and online combustion-ion chromatography. The results showed that the total fluorine and extractable organic fluorine contents in the 10 types of greaseproof paper were 330.15~1099.49 mg/kg and 39.20~101.83 mg/kg, respectively, and those in the 16 types of unprocessed raw paper were 15.33~121.03 mg/kg and 0~2.87 mg/kg, respectively. The total fluorine content in mineral fillers such as talc and bentonite used in food packaging paper was 174.03~688.20 mg/kg, which was much higher than that in other auxiliary materials and was the main source of fluorides in food contact paper. Most sizing agents, fungicides and other chemical additives had low levels of total fluorine content, ranging from 20.11 to 31.41 mg/kg. This study provides a research reference for the control of fluorides in food packaging paper.