Wilhelmus (full title: Wilhelmus van Nassouwe) is the national anthem of the Kingdom of the Netherlands.
Wilhelmus may also refer to:
People with the given name Wilhelmus
Wilhelmus à Brakel (1635–1711), Dutch Protestant Reformation theologian and minister Wilhelmus Beekman (1623–1707), Dutch-US politician Wilhelmus Bekkers (1890–1957), Dutch tug-of-war Olympic medalist and swimming instructor Wilhelmus Beurs (1656–1700), Dutch Golden Age painter Wilhelmus Braams (1886–1955), Dutch long-distance runner Wilhelmus Bryan (born ?), US documentary film producer Wilhelmus Demarteau (1917–2012), Dutch Roman Catholic prelate Wilhelmus Doll (1900–1980), Dutch wrestler and Olympic competitor Wilhelmus Simon Petrus Fortuijn (1948–2002), known as Pim Fortuyn, Dutch politician, civil servant, sociologist, author and professor Wilhelmus Frederik van Leeuwen (1860–1930), Dutch politician, mayor of Amsterdam (1901–10), and lawyer Wilhelmus Luijpen (1922–1980), Dutch philosopher and Catholic priest Wilhelmus Luxemburg (1929–2018), Netherlands-born US mathematician Wilhelmus Nuyens (1823–1894), Dutch historian Wilhelmus Wilhelmius (1720–1771), Dutch minister, mathematician, and philosopher Wilhelmus Zakaria Johannes (1895–1952), Indonesian radiologist
People with the surname Wilhelmus
Joop Wilhelmus (1943–1994), Dutch pornographer and entrepreneur
Other uses De Wilhelmus, the grand ducal anthem of Luxembourg Fort Wilhelmus, a fort on Burlington Island, New Jersey, USA