Defence of the Realm might refer to:

• Defence of the Realm, a 1985 political thriller film
• Defence of the Realm, a 1996 documentary about the workings of the British Armed Forces under the MoD
• The Defence of the Realm, a 2009 history of MI5 by Christopher Andrew
• Defence of the Realm Act 1803, an act of the United Kingdom parliament
• Defence of the Realm Act 1914, an act of the United Kingdom parliament
• Defence of the Realm Act 1915, an act of the United Kingdom parliament

• 1959 Guatemalan parliamentary election
• 1959 Hengchun earthquake
• 1959 Ice Hockey World Championships
• 1959 ICF Canoe Slalom World Championships
• 1959 in Brazilian football
• 1959 in British music
• 1959 in British television
• 1959 in cinema
• 1959 in Denmark
• 1959 Individual Speedway World Championship
• 1959 in films
• 1959 in football (soccer)
• 1959 in France
• 1959 in Israel
• 1959 in Japanese football
• 1959 in jazz
• 1959 in Luxembourg
• 1959 in Malaysia
• 1959 in NASCAR
• 1959 in Norway
• 1959 in paleontology
• 1959 in Taiwan
• 1959 in the cinema
• 1959 in the movies
• 1959 in the United States