Siwiec may refer to:

• Marek Siwiec
• Natalia Siwiec
• Ryszard Siwiec

• Kontaki
• Kontakio For You Departed
• Kontakion For You Departed
• Kontaktor
• Kontanawa language
• Kontanáwa language
• Kont Diga
• Kont Diġa
• KonTechs Ltd
• Konteki
• Konter
• Konter (disambiguation)
• Konterk
• Konterra Drive
• Konteyevo
• Konthamuru
• Konthayum Poonoolum
• Kontich-Lint railway station
• Kontienen
• Kon-Tiki
• Kontiki
• Kon-Tiki (1951 film)
• Kon-Tiki (2012 film)
• Kon-Tiki: Across the Pacific in a Raft
• Kon-Tiki (book)