The words defense or defence can refer to any of the following:

• For defense of a doctoral dissertation see thesis committee
• For the military term see defense (military)
• Civil defense measures and emergency preparedness
• In politics, defense may be a euphemism for war
• For legal defense see defense (legal)
• For defense in sport see defense (sport)

This disambiguation article uses the American English variant of the word. Defense is predominantly American English while Defence is used in all other English speaking countries, similar to offence/offense.