Willemsen may refer to:

• August Willemsen (1936–2007), Dutch translator of Portuguese and Brazilian literature
• Daniël Willemsen (born 1975), Dutch sidecarcross rider and nine times World Champion
• Elfje Willemsen (born 1985), Belgian bobsledder who has competed since 2007
• Madeline Willemsen (1915–1982), Puerto Rican actress and comedian
• Marcel Willemsen (born 1977), Dutch sidecarcross passenger and 1999 World Champion
• Mike Willemsen (born 1996), Dutch DJ, record producer, musician
• Roger Willemsen (1955–2016), German author, essayist and TV presenter

• Willems
• Willemse
• Wilhelmsen
• Willemsens
• Williamson (disambiguation)