The Ministry of Defence (MINDEF; Malay: Kementerian Pertahanan; Chinese: 新加坡國防部; Tamil: தற்காப்பு அமைச்சு) is a ministry under the Government of Singapore responsible for overseeing the national defence of Singapore.

MINDEF's mission is to "enhance Singapore's peace and security through deterrence and diplomacy, and should these fail, to secure a swift and decisive victory over the aggressor.

MINDEF has one statutory board, the Defence Science and Technology Agency (DSTA).

The Singapore Armed Forces (SAF), which consists of the Singapore Army, the Republic of Singapore Navy (RSN), the Republic of Singapore Air Force (RSAF), and the Digital and Intelligence Service (DIS), is a military component of MINDEF.

The Ministry is headed by the Minister for Defence, who is appointed as part of the Cabinet of Singapore.