The Ministry of Defence of Ukraine (Ukrainian: Міністерство оборони України, МОУ, romanized: Ministerstvo oborony Ukrainy, MOU) is the ministry of the Ukrainian government that oversees national defence and the Armed Forces of Ukraine. The head of the ministry is the Minister of Defence. The President of Ukraine is the Supreme Commander-in-Chief of the Armed Forces of Ukraine.

The ministry was established in Ukraine on 24 September 1991, one month after Ukraine's declaration of independence resolution. The ministry was put in charge of all Soviet military forces reorganization on the territory of Ukrainian jurisdiction. In 1994, Ukraine voluntarily gave up all nuclear weapons. The ministry spent significant funds eliminating nuclear weapons, military bases and equipment to meet Treaty on Conventional Armed Forces in Europe requirements.

In 2022 it was planned to provide 5% of Ukraine's GDP for the needs of the Ministry of Defence. In July 2022, amidst Russian invasion of Ukraine, the Ministry of Defence of Ukraine stated that it spends a years' budget of the ministry every month of the war with Russia.

As ratified by the Verkhovna Rada (Ukrainian parliament), the major objectives of the ministry are preventing hostility, structuring the military, and repelling all types of aggression (both in country and internationally). Ukrainian security policies are based on non-intervention, respect for the national borders and sovereignty of other states, rejecting any use of force as an instrument of influence.

Because of political sensitivity, the military doctrine, similar to Ukraine's security policy, does not point out a specific threats. It rather refers to a "states, whose consistent policy presents a military threat, or leads to interference in the internal affairs of Ukraine, or encroaches Ukraine's territorial integrity and national interests."

Hence, the Ministry of Defence is responsible for:

The first military executive office was created on 28 June 1917, as part of the General Secretariat of Ukraine and was headed by Symon Petliura. It was created based on the Ukrainian General Military Committee under the auspices of the Central Council of Ukraine. The Russian Provisional Government refused to recognize it, but after the October Revolution the Secretariat of Military Affairs was re-established on 12 November 1917. At the end of December 1917, Symon Petliura resigned in protest at the Treaty of Brest-Litovsk.

At the same time, Bolsheviks established their own executive branch as part of the People's Secretariat headed by Vasyl Shakhrai. On 6 January 1918, Volodymyr Vynnychenko appointed Mykola Porsh to the vacant position. On 25 January 1918, the general secretariats were reorganized into people's ministries as Ukraine proclaimed its independence. The [People's] Ministry of Military Affairs existed also during the regime of Hetman of Ukraine Pavlo Skoropadsky and until the exile of the Ukrainian National Government at the end of 1920.