Military Intelligence 6 (MI6 or MI6 Secret Intelligence Service) a British intelligence agency — was among the international intelligence agencies listed in the CTU Operations Manual. The agency had a building in Los Angeles.

Stephen Saunders worked for MI6 prior to Day 1 and was on loan to the US during an operation (codenamed Nightfall) to assassinate the war criminal Victor Drazen.

Morris O'Brian also began his career freelancing for MI6.

Day 3 Edit

Their office in Los Angeles was attacked around 5:45am by men sent by Stephen Saunders. Numerous MI6 agents, including Trevor Tomlinson, and the witness Diana White, were killed in the assault. Servers containing critical information were also destroyed by a C4 charge, but Jack Bauer managed to retrieve vital information pertaining to Saunders before the explosion.