The Roman wall of Barcelona is an archaeological and monumental complex made up of the remains of the ancient wall built in the time of the Roman Empire, between the 1st century BC and the 4th century BC. They are located in the Gothic Quarter, in the Old Town district of Barcelona.

The Roman Republic first entered the Iberian Peninsula during the Second Punic War to counter the power of the Carthaginians in the area, which eventually led to the beginning of the conquest of the territory, a slow process that would last almost two centuries, until the year 19 BC when the Emperor Augustus ended his control of the peninsula. The Roman bases of action in the area were initially Emporion and Rhodae, as well as the main Roman foundation in the territory, Tarraco.

During this period, the Romans probably occupied the Iberian enclave at Montjuic to control the mouth of the Llobregat, a strategic centre. It can also be assumed that during this period, acculturation took place between the native population and the new arrivals.

It seems that it was during the reign of Augustus (27 BC - 14 BC), which meant the conversion of the Roman Republic into an empire, that the colony that would give rise to the city was founded, christened Barcino, probably as a Latinisation of the Iberian name Barkeno. Founded between 15 BC and 10 BC, the settlement was located on a small promontory on the Barcelona plain near the coast, Mount Táber.

The main reason for choosing this site must surely have been its natural harbour, although the alluvium of the torrents and the sedimentation of sand from the coastal currents would have made the harbour's draught difficult. The new settlement was given the full name of Colonia Iulia Augusta Faventia Paterna Barcino. The first settlers seem to have been legionaries discharged from the Cantabrian Wars, freedmen from the Narbonensis and Italic colonists.

Barcino took the urban form of castrum initially, and later oppidum, with the usual organising axes cardo maximus and decumanus maximus; at the confluence of the two was the forum, the central square dedicated to public life and business. From this centre, the city followed an orthogonal layout, with square or rectangular blocks, following a grid layout based on two main axes: a horizontal and a vertical axial order, which would mark the future layout of the city, and would be taken up by Ildefonso Cerdá in his Plan de Ensanche of 1859. The strategic role of Barcino, the arrival point of the great northern - Via Augusta - and Mediterranean axes, gave the city an active commercial and economic development from very early on. The maximum splendour of the Roman period occurred during the 2nd and 3rd centuries, with a population that must have fluctuated between 3,500 and 5,000 inhabitants.

The Barcino enclosure was walled, with a perimeter of 1.5 km, protecting an area of 10.4 hectares. The first city wall, of simple construction, was begun in the 1st century BC. It had few towers, only at the corners and at the gates of the walled perimeter, of which there were four: the Praetoria, the Decumana, the Principalis Sinistra and the Principalis Dextra. However, the first incursions by Franks and Alamanni from the 250s onwards made it necessary to reinforce the walls, which were extended in the 4th century.

The new wall was built on the foundations of the first and consisted of a 2-metre double wall with a space in between filled with stone and mortar. The wall consisted of 81 towers about 18 m high, most of which had a rectangular base.

Various remains of the old wall have been preserved, especially from the northern and eastern sections. The main remains are in the Piazza Nuova, where the Praetoria gate was located: two of the towers, part of the perimeter wall and an arcade of the old aqueduct that carried water to the city are preserved here. The houses of the Dean and the Archdeacon were built on this section. From here it continues along Tapineria street, where a polygonal tower that formed the northern corner of the enclosure is still preserved; this part of the wall served as a support for the rear wall of the house of the Pia Almoina.

This section continues in the Plaza de Ramón Berenguer el Grande, where, on top of the Roman wall, there are remains of the medieval wall; on this base stands the chapel of Santa Ágata. The wall continues along Carrer Sotstinent Navarro, where the palace of Requesens was built over a pointed vault. In Carrer del Correu Vell there is a circular tower that formed one of the corners of the wall. There is also a section in Traginers square, where another of the towers is preserved.

Small remains are preserved in the streets Regomir, Avinyó, Call, Banys Nous and Palla, generally inside various private buildings. Some remains of the wall are also preserved in the basement of the Barcelona History Museum, as well as the remains of various buildings from Roman Barcino. There are also remains of the old Sea Gate at the Pati Llimona Civic Centre in Carrer Regomir.