Santa Maria in Campo Carleo was a parish church that used to stand on the south side of the junction between Via Alessandrina and Strada dei Conti (which led to the Piazza del Grillo), but was demolished in 1864 in the early stages of the clearing of the area of the Imperial Fora.
The dedication was latterly to the Immaculate Conception.
It was an early foundation as a parish church, but has its first unambiguous mention in the Catalogue of Turin, c1320 as Santa Maria appresso Sant'Urbano. It may have been a church referred to as Santa Maria di Kaloleo in about the year 1000, and is thought to have been founded about then. A theory is that this Kaloleo was a Byzantine official, and that he gave his name to the locality of Campo Carleo. The name is first recorded in 1461.
At the end of the 15th century it also had the name of Santa Maria a Spoglia Cristo, because over the entrance was a relief of Christ being stripped of his clothes before his crucifixion. This apparently caused offence to Pope Sixtus V (1585-90), who ordered the old image replaced by a fresco of Our Lady by Mario Arconio. An alternative dedication first recorded in 1492 was to San Salvatore.
There was a major restoration or rebuilding in the 16th century.
There seems to be some confusion as to when the church was actually demolished. Hülsen quotes 1864, but 1862 and 1884 are also given. Pope Pius IX undertook to clear the Forum of Trajan before he lost temporal power in 1870.
A line continuing the southern arc of Trajan's Market will intersect two stubs of columns to the east of the present Via Alessandrina. The church was about here.
The plan was rectangular, but the façade was at an angle to the major axis so that the left hand side wall was shorter than the right. The church intruded into the Via Alessandrina, not following the line of the frontage on the east side of the street but angled so that the façade narrowed the street at the crossroads. This is some evidence of the church's antique origins.
There was an unaisled nave with four pilasters supporting the ceiling, a triumphal arch and a square apse. Two side chapels existed, the one on the right dedicated to Christ the Saviour and the one on the left to SS Blaise, Roch and Sebastian. The former dedication may recall the lost church of San Salvatore alle Milizie which stood on the east side of the nearby Salita del Grillo until the end of the 16th century.
It was a small building with a façade topped by a triangular pediment containing an oculus window. The doorway also had a triangular pediment. Above this, and extending into the pediment as far as the window, was the fresco of the Madonna and Child surrounded by a complex stucco frame. This was flanked by a pair of rectangular windows.
There was no campanile, but a little bellcote over the left hand side wall having a gabled top and containing one bell.
A Vasi engraving shows the church as it was in the 18th century, but the artist took liberties with the width of the street. It was much narrower than he depicts it. See "Rome art lover" web-page.