英国“军情五处”（Military Intelligence 5），是世界上最具神秘色彩的谍报机构之一。
1905年英国陆军大臣R·B·霍尔丹实施的军队改革促使军事情报部门的成立。但是总参谋部为情报部门的归属问题却争论不休，争论的结果导致MI5（军情5处）的成立，它起先归属于陆军部，后来由外交部接管。
军情五处成立以来，在对付颠覆和恐怖活动上立下累累战功,一度拯救英国于危亡之中。
MI5成员标准
具有良好的人际交流技巧和团队合作精神；
对生活经常遭受干扰要有很强的承受能力；
严格遵守纪律；
对身边发生的任何一件小事都要有准确记忆；
具有优良的判断能力；
具备高超的驾驶技术，达到高级驾驶标准；
必要时有根据情况随机应变的能力；
会使用各种高科技设备。
成立目标:
frustrate terrorism;
prevent damage to the UK from foreign espionage and other covert foreign state activity;
frustrate procurement by proliferating countries of material, technology or expertise relating to weapons of mass destruction;
watch out for new or re-emerging types of threat;
protect Government's sensitive information and assets, and the Critical National Infrastructure (CNI);
reduce serious crime through assistance to law enforcement agencies;
assist the Secret Intelligence Service (SIS) and the Government Communications Headquarters (GCHQ) in the discharge of their statutory functions;
build Service capability and resilience.
历任掌门人：
Major-General Sir Vernon Kell (1873-1942)1st Director General, 1909-1940
Brigadier A.W.A. Harker 2nd Director General, 1940-1941
Sir David Petrie (1879-1961) 3rd Director General, 1941-1946
Sir Percy Sillitoe (1888-1962)4th Director General, 1946-1953
Sir Dick White (1906-1993)5th Director General, 1953-1956
Sir Roger Hollis (1905-1973)6th Director General, 1956-1965
Sir Martin Furnival Jones (1912-1997)7th Director General, 1965-1972
Sir Michael Hanley (1918-2001)8th Director General, 1972-1978
Sir Howard Smith (1919-1996)9th Director General, 1978-1981
Sir John Jones (1923-1998)10th Director General, 1981-1985
Sir Antony Duff (1920-2000)11th Director General, 1985-1987
Sir Patrick Walker (1932- )12th Director General, 1987-1992
Dame Stella Rimington (1935- )13th Director General, 1992-1996
Sir Stephen Lander (1947- )14th Director General, 1996-2002
