Paleovirology, the study of viruses from historical or ancient samples, is a relatively unexplored but promising subfield of ancient DNA (aDNA) and paleogenomic research. Analysis of viruses, even over short historical timescales, can provide information on virus evolution and biology that may be difficult or impossible to obtain from examining current viral diversity. This is in part because the rapid evolution and proneness to extinction of strains of many viruses can quickly obscure their origins. Though exceptionally difficult to characterize from ancient DNA or RNA extracts, reports on the successful analysis of historical and ancient viruses have been steadily accumulating. In this chapter, we summarize the successes and failures in this new emerging field.