The fountain, at the junction of three roads (tre vie),[3] marks the terminal point[4] of the "modern" Acqua Vergine—the revived Aqua Virgo, one of the aqueducts that supplied water to ancient Rome.

In 19 BC, supposedly with the help of a virgin, Roman technicians located a source of pure water some 13 km (8.1 mi) from the city.

Although compromised and greatly reduced in scope after the damage caused by the siege of the Goths of Vitiges in 537, the Acqua Vergine remained in use throughout the Middle Ages, with restorations attested as early as the 8th century, then again by the Municipality in the 12th century, on the occasion of which the conduit was also connected to other sources closer to the city, located in a place then called "Trebium".

[10] Salvi died in 1751 with his work half finished, but he had made sure a barber's unsightly sign would not spoil the ensemble, hiding it behind a sculpted vase,[11] called by Romans the asso di coppe, the "Ace of Cups", because of its resemblance to a Tarot card.

[12] Four different sculptors were hired to complete the fountain's decorations: Pietro Bracci (whose statue of Oceanus sits in the central niche), Filippo della Valle, Giovanni Grossi, and Andrea Bergondi.

[14] The Trevi Fountain was finished in 1762 by Pannini, who substituted the present allegories for planned sculptures of Agrippa and Trivia, the Roman virgin.

[16] The majority of the piece is made from Travertine stone, quarried near Tivoli, about 35 kilometres (22 miles) east of Rome.

[27][28] Ryan Maue, the former chief scientist for the National Oceanic and Atmospheric Administration, stated the attack was done by "climate eco-anarchists".

[29] The backdrop for the fountain is the Palazzo Poli, given a new façade with a giant order of Corinthian pilasters that link the two main storeys.

In the niches flanking Oceanus, Abundance spills water from her urn and Salubrity holds a cup from which a snake drinks.

[31] The Tritons and horses provide symmetrical balance, with the maximum contrast in their mood and poses[citation needed] (by 1730, Rococo was already in full bloom in France and Germany).

[46] In Federico Fellini's 1960 film La Dolce Vita, Anita Ekberg wades into the fountain with Marcello Mastroianni.

[48] Another copy is located near Caesars Palace in Las Vegas,[49] and another replica can be found in Jamsil station of the Seoul Metro Subway.