Hermanus is a Latinized version of the Germanic masculine given name Herman. It and its less common variant Hermannus have been used in the Low Countries and South Africa as a birth name. Most people use a short form, like Herman, Harm, Harmen, and Manus. Hermanus also is a patronymic surname in South Africa. People with the name include:

As a Latinized name Hermannus Alemannus (died 1272), German bishop in Spain and translator of Arabic philosophical works into Latin Hermannus Contractus (1013–1054), German scholar, composer, music theorist, mathematician, and astronomer Hermannus Dalmata (c.1100–1160), Istrian philosopher, astronomer, astrologer, mathematician, translator and author Hermannus de Wartberge (died c.1380), Livonian chronicler Hermannus Witsius (1636–1708), Dutch theologian

As a birth name Hermanus Angelkot (1688–1727), Dutch pharmacist, poet and playwright Hermanus Hendrikus Baanders (1849–1905), Dutch architect Hermanus Berserik (1921–2002), Dutch painter and print maker Hermanus Beukes (1913–2004), Namibian politician and activist Hermanus Blom (1885–1963), Dutch actor, screenwriter and playwright known as Herman Bouber Hermanus Brockmann (1871–1936), Dutch rower Hermanus Brood (1946–2001), Dutch musician and painter. Hermanus van Brussel (1763–1815), Dutch landscape painter and etcher Hermanus Jacob Coster (1865–1899), Dutch lawyer and Second Boer War lieutenant Hermanus Johannes de Graaf (1899–1984), Dutch historian of Java Hermanus Haga (1852–1936), Dutch physicist Hermanus P. J. B. Heinsbroek (born 1951), Dutch Minister of Economic Affairs Hermannus Höfte (1884–1961), Dutch rower Hermanus Koekkoek (1815–1882), Dutch landscape painter Hermanus Willem Koekkoek (1867–1929), Dutch military scenes painter Hermanus Ellen Mees (1880–1964), Dutch painter, draftsman, and lithographer Hermanus Meyer (1733–1791), German-born clergyman of the Dutch Reformed Church in America Hermanus Numan (1744–1820), Dutch painter, draftsman, and publisher Hermanus J.A.M. Schaepman (1844–1903), Dutch priest, politician and poet Hermanus Eliza Verschoor (1791–1877), Dutch liberal politician Hermanus L. W. Vrauwdeunt (1915–1982), Dutch footballer Hermanus van Wyk (1835–1905), South African Baster settler in Namibia

As a surname Grant Hermanus (born 1995), South African rugby player Kartini Hermanus (1949–2021), Indonesian military officer Oliver Hermanus (born 1983), South African film director and writer

See also Hermanus, a town in South Africa named after the Dutch teacher Hermanus Pieters Hermanus Magnetic Observatory, a research facility near that town Harmanus