In this study, the development of electrically-heatable carbon thin films (CTFs) from water-soluble poly(vinyl alcohol) (PVA) is described. CTFs are easily obtained by room-temperature and solid-state proton irradiation-induced stabilization of PVA thin films followed by carbonization at a high temperature. The results of the chemical, optical, and structural analyses reveal that polyene-network structures, enabling high-temperature dimensional stability, are effectively created in the PVA thin films by combined reactions of crosslinking and dehydration during proton irradiation; these structures are further converted to pseudo-graphitic CTFs by carbonization. The prepared CTFs exhibit the fluence and thickness-dependent electrical conductivity ranging from 0.8 x 10(2) to 2.63 x 10(2)S cm(-1), and a very low surface roughness of below 0.41 nm. Moreover, the prepared CTFs show excellent electric-heating characteristics and the performance is clearly dependent on the thickness and fluence. The CTFs prepared in this study have good potential for application in the fabrication of automobiles, smart windows, and medical devices for deicing, defrosting, and warming.