This paper reports the findings of an archaeometric study performed on 14 architectural earthenwares from the archaeological site of S. Omobono, located in the historic center of Rome (Italy). The archaeological site, accidentally discovered in 1937, includes the remains of a sacred area previously occupied by two temples, one of which was converted into the church of S. Omobono, in 1575. The samples, dated between the 7th and the 6th century BC, belong to different sectors of the site. Their petrographic, mineralogical and geochemical characterization was performed by optical microscopy (OM), X-ray powder diffraction (XRPD), X-ray fluorescence (XRF), electron probe micro-analysis (EPMA), and Raman spectroscopy (RS). The compositional data obtained were also subjected to the principal component analysis (PCA) in order to highlight similarities and differences among the samples. By combining geochemical and petrographic data, we were able to identify several different fabrics. Furthermore, the study provided valuable information on the firing temperatures of some samples and the provenance of the raw materials, by analyzing the chemical composition of clinopyroxenes present as non-plastic inclusions.