The banknotes of the former colony of São Tomé and Príncipe form an essential component of Portuguese ultramarine paper‑money, comprising fiduciary issues produced from the 19th century to 1975 to support the economic and administrative needs of the archipelago. Issued mainly by the Banco Nacional Ultramarino, these series include banknotes, certificates, specimens and fiduciary documents that illustrate monetary reforms, evolving denominations, territorial iconography and the financial structure of the colonial administration. Their historical relevance, artistic diversity and rarity make them highly valued by collectors and researchers studying Portuguese overseas monetary history. Banknotes issued after the independence of São Tomé and Príncipe are not part of this category and are listed under Foreign Banknotes → Africa → São Tomé and Príncipe.