All these indicate the presently-accepted site for this temple, just north of the theatre and east of the porticus Octaviae, on the street leading through the porta Carmentalis to the campus Martius, a little south of the present Piazza Campitelli.

The three columns of the temple which survive to full-height today belong to the Augustan rebuild, but the cult of Apollo had existed in this area since at least to the mid-5th century BC when an Apollinar (a sacred grove or altar) was recorded on this site.

Only minor reconstructions are known after the Augustan phases, by the urban prefect Memmius Vitrasius Orfitus (356 - 359) and perhaps by Anicius Acilius Fortunatus Glabrio in the 420s.

The temple would have been closed during the persecution of pagans in the late Roman Empire, when the Christian Emperors issued edicts prohibiting all non-Christian worship and sanctuaries.

These include: Between 37 and 32 BC, a large reconstruction of the pediment of the Temple of Apollo Sosianus occurred under Augustus, which was indicative of his larger plans to re-structure the architectural format of Circus Flaminius, an oval shaped section in the southern portion of Campus Mauritius.

While the original position of this sculpture has been the object of scholarly debate, as some authors believed that this work was originally placed in a niche within the temple cell,[23] this theory was disproved with the discovery of “a very accentuated stucco which hid a quadrangular hole, by those that are normally used to fix the pedimental statues with a hook to the back wall.”[23] Based on the location of this hole, scholars discovered that the Apollo statue would have been hung on the pediment with a profile view, and his left arm most likely held a shield while he held a sword in his right hand.

The remains of the podium wall surviving beneath the cloisters of Santa Maria in Campitelli – 13 metres long, over 4 high and over 2 thick – were assumed by Delbrück to be unquestionably a part of the original structure.

[26] The temple's hexastyle elevation was formed of Carrara marble columns along the front and the two long sides of the pronaos, with those at the back made of plastered brick.

The capitals are Corinthian with extra vegetable motifs (in Italian, "corinzieggiante", no English equivalent), and the frame presents a very protruding ceiling supported by brackets.

The cella's interior walls were decorated with a double order of column shafts in African marble, the lower one with a frieze representing stages of the battles included in the triple triumph of Octavian in 29 BC.

The architectural decoration of the surviving phase includes different and unusual motifs (e.g. the grooves of the column trunks, which are not all equal, but alternately wider and narrower).