This study examines the historical occurrence of the harbour porpoise (Phocoena phocoena) in Finnish coastal waters using a dataset of 413 records derived from digitised Finnish press, written in Finnish and Swedish, from the 19th century to the 1970s. The records identified through multilingual search terms, and analysed by time and location, reveal that porpoises were encountered across the Finnish coastline, particularly in summertime from 1828 to 1939, but sightings declined sharply after the 1940s. Most reported individuals were adults. In addition to occasional encounters, porpoises were frequently killed or caught as bycatch in fisheries. The study demonstrates the value of historical datasets in reconstructing long-term population changes and demonstrates the potential of combining cultural-historical and ecological perspectives. It provides new insights into the human-porpoise relationship and supports conservation efforts for this critically endangered Baltic population by integrating digitised archival materials with ecological interpretation.