Anton Willem Nieuwenhuis (22 May 1864 – 21 September 1953) was a Dutch explorer and physician who travelled extensively in central Borneo in the 1890s, recording valuable ethnographic information about the Dayak people and making biological collections. In 1904, Nieuwenhuis was appointed professor of geography and ethnology at Leiden University and became the editor of the journal Internationales Archiv für Ethnographie. He retired in May 1934 and died in his new hometown in 1953. In an obituary, Bertram E. Smythies called him "a Borneo Livingstone".