He was elected as a consul in 242 BC, a novus homo. During his consulship he supervised the construction of a new Roman fleet. This fleet was funded by donations from wealthy citizens, since the public treasury was virtually empty. He then led the fleet into victory over Hamilcar Barca's Carthaginian fleet in the Battle of the Aegates Islands. This was the decisive battle of the First Punic War. To celebrate his victory, he built a temple to Juturna in Campus Martius, in the area currently known as Largo di Torre Argentina.
Gaius Lutatius Catulus is also the main character of Finnish writer Jukka M. Heikkilä's book Merikonsuli.