Proto-Celtic religion lacks unified system but features reconstructed deities like *Lugus and *Toranos identical to Germanic Thor. Druids (*druwides) were oak-knowing priests shared across Celtic branches. Bards (*bardos) and seers (*wātis) held sacral roles in Proto-Celtic society. Sacred groves (*nemetom) served as central sanctuaries. Thunder god *Toranos wields lightning from PIE *stenh₂-. War divinity *Bodwos cognates with Germanic battle goddess Baduhenna. Earth goddess *Brigantī linked to hills and rivers. Smith god *Gobann- appears in Gaulish, Irish, Welsh myths. Mother goddesses *Mātronā widespread in Gaul and Britain. Healing god *Nowdont- associated with dogs and water. One-eyed epithet ?*Kaiko- parallels Odin’s Hárr. All-father ?*Olo-(p)atīr matches Germanic Ala-fader for Dagda and Odin. White god *Windos evolves into Irish Finn and Welsh Gwyn. White spectre ?*Windo-sēbrā origins Guinevere and Findabair. Three worlds: upper *albiyos, living *bitus, lower *dubnos. Ghosts called *drougos identical to Germanic draugaz. Incubus daemon *dwosyos abused women in Gaulish lore. Female demon *morā shared with Germanic marōn. Demons *skāhslo- cognate to Gothic evil spirits. Poets inspired by *awe- as breathed-in genius. Offerings *adbertā and summoners *adgaryos central to rituals. Souls termed *anamones from PIE breath-root. Holy status *noybo- and sacred *sakro- mean consecrated or cursed. Magic *soyto- binds like Germanic saidaz. Festivals like *samoni- assemble living and dead. Proto-Celtic shares motifs with wider Indo-European traditions.