Juno Regina, or Juno the Queen, is Juno in Her aspect of Queen of the Gods and Queen of Heaven. As Queen, She holds the sceptre and the patera (a shallow dish for making ritual offerings) and wields the thunderbolt. She is frequently shown wearing a royal diadem and a long veil; the magnificent peacock is Her bird, and the aurata iuvenca, ("gilded heifer", presumably a young cow whose horns have been gilt) is the animal considered proper to offer in Her sacrifices. She protected the Roman people, and with Her consort Jupiter and His daughter Minerva She headed the state cult. The three of them made up the Capitoline Triad, whose worship can be traced back to the Etruscan triad of Uni, Tinia and Menrfa. These three were worshipped in the great joint temple on the Capitoline Hill of Rome, usually called the temple of the Capitoline Triad or the temple of Jupiter Optimus Maximus ("Bestest and Greatest Jupiter"), as His was the central of the three cellae (temple chambers). This temple had very ancient origins—tradition ascribes it to Tarquinius Priscus, an early King of Rome said to have ruled in the late 6th century BCE and considered more legendary than historic. Juno had Her cella to the left, Minerva to the right; and in this temple were also two smaller shrines to the God Terminus and Goddess Iuventas, who had been a part of a sanctuary to multiple Gods formerly on the site and who refused to move! Each of the Triad had Her/His own hearth-altar, and though it is not known for sure what the cult-statues of Juno and Minerva looked like, they were probably of the same style and early date as Jupiter's, which was of Etruscan workmanship and made in terracotta. Being on top of a hill this temple was prone to being hit by lightning and burnt several times in various fires, each time being rebuilt more magnificently than the last. It became customary to store treasures dedicated to the state there, and in fact these treasures had to be removed at least once to make more room, as they were clutterin' up the place. It was considered the most majestic temple in Rome, with its gilded roof-tiles, gold-plated doors and columns of white Pentelic marble shipped all the way from Greece.

The ritual of removing a Deity from one sacred and dedicated location is called evocation; this is the process that Terminus and Iuventas refused to take part in. The Juno (or rather, Uni) of the Etruscan city of Veii (Veia to the Etruscans) was according to tradition persuaded to abandon Her besieged city after the Roman general/dictator Camillus vowed a splendid temple to Her in Rome, and promised Her greater honors there. That, at any rate, is the Roman version of things; and in 392 BCE the temple to Juno Regina on the Aventine Hill was dedicated on September 1st. The xoanon (archaic wooden statue) of Uni was brought to Her new home, and the Goddess received offerings there primarily from women; later, during a time of national crisis, Juno was given offerings that had formerly been made to other Gods. This Juno's Etruscan origins changed the character of Juno Regina in Rome, and She became more of a protective Deity who was regarded as a saviouress.

The Juno Regina of Veii may also be connected with the idea of the Queen who represents the land, and whose approval is required before sovereignty can be granted; and this may be part of why She was especially invoked for protection during the Second Punic War, when the foreign general Hannibal invaded Italy. During this war, which dragged on from 218-201 BCE, the matrons (married women) of Rome organized and donated gifts to the temple of Juno Regina on the Aventine, seeking protection on behalf of all the people. It was commonly believed at this time that the Gods were angry with Rome, and the thinking could have been that Juno Regina, as a Goddess of foreign origin from a conquered city, was especially likely to be angry with Rome and so favor the Carthaginians in this conflict as payback for Veii, or, that She could be easily wooed away from Rome if the opportunity arose, as She had been from Veii.

Juno Regina had yet another temple in Rome, in the Circus Flaminius (not properly a Roman circus—what we'd call a horse track—but more a large square where triumphs were held). This temple was vowed by Lepidus and built in 179 BCE, next to the temple of Jupiter Stator, with whom She was associated. Her temple was considered a natural complement to Jupiter's, and was the obvious choice of next in line to be built. It was connected to a temple of Fortuna by a portico, and both Her temple and Jupiter's were home to many famous works of art. A tale, dating to the restoration of both temples by Octavia sometime during the reign of her brother Emperor Augustus, says that the workmen got confused during the restoration and got the decorations and statues swapped by accident. Whether or not that's true, it does indicate that the two temples were of a similar size and importance, which further implies that the two Deities were of an equal importance. The ruins of Juno Regina's temple in the Circus Flaminius are still there, and three of the columns, standing in their original positions, have been incorporated into the wall of a later building.

Juno Regina held a central place in Roman religion, as a representation of the women of Rome; and She had powers of protection, like a mother or queen. In the temple on the Capitoline, the three hearth-altars of Juno, Jupiter and Minerva are also representative of their central role as a group; the hearth is the symbol of the center, whether it's the hearth of the house, often used as an altar in offerings to the Lares, or the hearth hosting the perpetual flame in the Temple of Vesta in the Forum, representing the heart of Rome.