In this work, we present the preliminary results of the archaeometric analysis of several ceramic and clay samples from two Celtiberian hillforts of the Iron Age from the Spanish Central Plateau: El Ceremeño and its cemetery (Early and Middle Iron Age) and the oppidum of Los Rodiles (Late Iron Age) including La Rodriga, a potter's workshop contemporary to Los Rodiles. Clay samples were collected from all sites in order to carry out a provenance analysis and to determine if the ceramic production of the proposed archaeological sites was local or foreign. Mineralogical analysis was performed by Thin-Layer Petrography (TLP) and XRay Diffraction (XRD), whereas chemical analysis was done by X-Ray Fluorescence: Semi-quantitative (XRF) and Trace Elemental analysis (XRF-t). Moreover, to complete the study a thermal analysis was carried out by a dilatometer (DLT). Although the number of samples evaluated was limited, in all the studied cases, the analyzed pottery was clearly found to be made with the clay from the surroundings of the archaeological sites.