Defence or defense (American spelling) can refer to:

• Defence (military)
• Defence (sport)
• Defence (legal)
• Civil defence
• Defence industry
• Self-defence
• Self-defence (theory) and defence of property, legal justifications
• Planetary defence, including the conference and science fiction

Defence or defense may also be:

• A euphemism for war
• Defence of a doctoral thesis, also called viva voce; see Thesis committee
• La Défense, a business district of high-rise buildings to the west of Paris

Defensie | Defesa