The Federal Security Service of the Russian Federation is the principal security agency of Russia and the main successor agency to the USSR's Committee of State Security (KGB).

Its main responsibilities are within the country and include counter-intelligence, internal and border security, counter-terrorism, and surveillance as well as investigating some other types of grave crimes and federal law violations. It is headquartered in Lubyanka Square, Moscow's centre, in the main building of the former KGB. The Director of the FSB since 2008 is army general Aleksandr Bortnikov.