Caecilius may refer to:

• Caecilia gens, an ancient Roman family, including a list of people with the name
  • Lucius Caecilius Iucundus, a Roman inhabitant of Pompeii, and central character in the Cambridge Latin Course series
• Caecilius (insect), a genus of insect
• Kusaila (Latin: Caecilius), a 7th-century Berber king

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