The Ministry of Defence (Sinhala: රාජ්‍ය ආරක්ෂක අමාත්‍යාංශය Rājya ārakshaka amāthyanshaya; Tamil: பாதுகாப்பு அமைச்சகம்) is the cabinet ministry of the Government of Sri Lanka responsible for implementation of government defence policy and acts as the overall headquarters of the Sri Lankan Armed Forces.

The Ministry of Defence states that its principal objectives are the formulation, co-ordination and the execution of policies in relation to the national security.

With the end of the Cold War, the MOD does not foresee any short-term conventional military threat, the main threat to Sri Lanka having been the now-defunct organization, the LTTE and Islamic Terrorism.

In 1999 the National Security Council was established removing the direct control the military from the deputy Minister of Defence.

[2] Since the establishment of the MoD in 1978 the portfolio of Minister of Defence was held by the President of Sri Lanka, except for a few brief periods .