Cissonius (also Cisonius, Cesonius) was an ancient Gaulish/Celtic god. After Visucius, Cissonius was the most common name of the Gaulish/Celtic Mercury; around seventeen inscriptions dedicated to him extend from France and Southern Germany into Switzerland.
Cissonius was represented either as a bearded, helmeted man riding a ram and carrying a wine cup, or else as a young man with winged helmet and herald's staff accompanied by a rooster and goat.
The name has been interpreted as meaning "courageous", "remote" or else "carriage-driver". He was probably a god of trade and protector of travellers, since Mercury exercised similar functions in the Roman pantheon.
In one inscription from Promontogno in Switzerland, Cissonus is identified with Matutinus.
- Nicole Jufer & Thierry Luginbühl. 2001. Les dieux gaulois : répertoire des noms de divinités celtiques connus par l'épigraphie, les textes antiques et la toponymie. Editions Errance, Paris. pp.34-5
- J.-J. Hatt (1989), Mythes et dieux de la Gaules, I : les grandes divinités masculines, Paris, p.217. Cited in William van Andringa (2002). La religion en Gaule romaine : Piété et politique (Ier-IIIe siècle apr. J.-C. Editions Errance, Paris. pp.135,155. Van Andringa thus summarizes Hatt's conclusions: "Cissonius dériverait du gaulois cissum, voiture." ("Cissonius would be derived from the Gaulish cissum, carriage.")
- Dictionary of Celtic Myth and Legend, Miranda J. Green, Thames and Hudson Ltd, 1997