Disclosed is a polyamide-imide precursor having a molecular structure in which a first polymer, derived from polymerization of a dianhydride and a diamine, and a second polymer, derived from polymerization of a diamine and an aromatic dicarbonyl compound, are copolymerized, wherein the diamine includes 3 to 50 mol % of at least one of 9,9-bis(4-aminophenyl)fluorene (FDA) and 9,9-bis(4-amino-3-fluorophenyl)fluorene (F-FDA), based on the total molar amount of the diamine. Also, a copolymerized polyamide-imide in which the polyamide-imide precursor is imidized or a copolymerized polyamide-imide film formed by an imidization reaction of the polyamide-imide precursor and an image display device including the copolymerized polyamide-imide film are provided.