In Roman mythology, Quirinus was a mysterious god.

At first he probably was a Sabine god. Sabines had a settlement near the future site of Rome, and they called one of their sites, in which they had erected an altar, the Collis Quirinalis ("Quirinal Hill") after Quirinus; this area was later included among the Seven hills of Rome, and Quirinus became one of the most important gods of the state, as associated with Romulus.

His name derives from co-viri "men together"; as such, he embodied the military and economic strength of the Roman populus collectively. He also watched over the curia "senate house" and comitia curiata "tribal assembly", the names of which are cognate with his own.

Quirinus' wife was Hora.

In art, he was portrayed as a bearded man with religious and military clothing.

He was sometimes associated with the myrtle plant.

His festival was the Quirinalia, on February 17.

Cited in Virgil's Aeneid I, 292

Roman citizens were sometimes called "Quirites" after Quirinus, and considered the title an honor (Livy).