This project presents a diachronic, comprehensive study of the archaeological record of sacrifice and the site-specific character of the ritual in Republican Rome and Latium. I focus on the multiple altars at five highly particular yet representative sanctuaries, with dates spanning the entire Republican era—S.Omobono in Rome, the Thirteen Altars at Lavinium, Area A at Fosso dell’Incastro at Ardea, the Republican Temples at Ostia, and Largo Argentina in Rome. My project places Roman sacrificial ritual at its particular monumental altar, in its proper temporal, geographic, architectural, and topographic space, and reintegrates contextually associated votives and the organic remains of sacrifice within the overall spatial framework of each sanctuary. While we cannot hope to re-create fully the experiential aspect of Roman sacrifice, by reexamining and supplementing existing archaeological data innovatively, I aim to clarify each aspect of the sacrificial procedure (from the procession of the animal to its slaughter to its cooking to the ritual cleansing of the area), allowing for the integration of the ritual within its larger material and topographical setting and within its logistical and technological infrastructure.