Natalis de Wailly (10 May 1805, Mézières, Ardennes – 4 December 1886, Paris) was a French archivist, librarian and historian. In 1841, as head of the Administrative Section of the Royal Archives, he wrote a ministerial circular, issued by Count Tanneguy Duchâtel, Minister of the Interior, stating that records should be grouped according to the nature of the institution that has accumulated them and formulating the principle of respect des fonds (up until that point, archives had often been sorted according to subject, date or place).