Gaius Atinius served as military tribune in Gaul under the consul Tiberius Sempronius Longus in 194 BC. He is probably the same Gaius Atinius who served as praetor in 188, and received Hispania Ulterior as his province. He remained there as propraetor, defeating the Lusitani, before being killed during the siege of Hasta in 186 BC.