In 2024, the Canadian government lifted the moratorium on fishing in what was once the world’s largest single-species fishery. Over the past thirty years, fisheries scientists and historians have debated the role of long-term exploitation in the fishery’s collapse, but a lack of accurate historical catch data has hampered these discussions. This study introduces a groundbreaking reconstruction of historical cod catches in Newfoundland from 1508 to 2023. As the the longest, most comprehensive, and accurate reconstruction created to date, this dataset provides a crucial tool for unravelling the complex dynamics of the fishery’s rise and fall. The data illuminate the historical trajectories of diverse national fishing fleets and maps the evolving spatial dimensions of the fishery. The dramatic decline of the fishery from centuries of relatively stable catches should prompt concern about the recent return to fishing, and historical data must play a role in informing the fishery’s future.