Isosa is a Celtic goddess worshipped in Gaul; she is known only from inscriptions in Etrechy, France, where she was accompanied by her fellow deities Carantana, Etiona, Gnatus, and Hidua.
Isosa received votive and dedicatory offerings from her worshippers; otherwise little is known of the specifics of her cult.
The origin of Isosa’s name is uncertain; I’ve seen it suggested that it derives from the same source as that of the god Esus, so that it may come from the Indo-European *eis- or “power.”
Another possibility is that it comes from the Proto-Celtic *isos or “sharp point, fibula, pin” as one would find in a clasp or brooch.
Isosa is known from inscriptions found in Etrechy, France.