Romulus and Remus are Rome's twin founders in its traditional foundation myth. They are descendants of the Trojan prince and refugee Aeneas, and are fathered by the god Mars or the demi-god Hercules on a royal Vestal Virgin, Rhea Silvia, whose uncle exposes them to die in the wild. They are found by a she-wolf who suckles and cares for them. The twins are eventually restored to their regal birthright, acquire many followers and decide to found a new city.

Romulus wishes to build the new city on the Palatine Hill; Remus prefers the Aventine Hill. They agree to determine the site through augury. Romulus appears to receive the more favourable signs but each claims the results in his favour. In the disputes that follow, Remus is killed. Ovid has Romulus invent the festival of Lemuria to appease Remus' resentful ghost. Romulus names the new city Rome, after himself, and goes on to create the Roman Legions and the Roman Senate. He adds citizens to his new city by abducting the women of the neighboring Sabine tribes, which results in the combination of Sabines and Romans as one Roman people. Rome rapidly expands to become a dominant force, due to divine favour and the inspired administrative, military and political leadership of Romulus. In later life Romulus becomes increasingly autocratic, disappears in mysterious circumstances and is deified as the god Quirinus, the divine persona of the Roman people.

The legend of Romulus and Remus encapsulates Rome's ideas of itself, its origins, moral values and purpose: it has also been described as one of the most problematic of all foundation myths. Romulus' name is thought to be a back-formation from the name Rome; Remus' is a matter for ancient and modern speculation. The main sources for the legend approach it as history and offer an implausibly exact chronology: Roman historians dated the city's foundation variously from 758 to 728 BC. Plutarch says Romulus was fifty-three at his death; which reckoning gives the twins' birth year as c. 771 BC. Possible historical bases for the broad mythological narrative remain unclear and much disputed. Romulus and Remus are eminent among the feral children of ancient mythography.