Ministry of War may refer to:

• Ministry of War (imperial China) (c. 600–1912)
• Chinese Republic Ministry of War (1912–1946)
• Ministry of War (Kingdom of Bavaria) (1808–1919)
• Ministry of War (Brazil) (1815–1999)
• Ministry of War (Estonia) (1918–1928; 1937-1940)
• Ministry of War (France) (1791–1947)
• Ministry of War (Italy) (1861–1947)
• Ministry of War (pre-modern Japan) (702–1872)
• Ministry of War (Japan) (1872–1945)
• Ministry of War (Peru) (1920–1987)
• War Ministry (Portugal) (1820–1974)
• Prussian Ministry of War (1808–1919)
• Ministry of War of the Russian Empire (1802–1917)
• Ministry of War of Saxony (1831–1919)
• Ministry of War of Württemberg (1806–1919)

• Ministry of defence, a type of government department
• Department of Defence
• War Department
• War cabinet, a committee formed by a government in a time of war
• Chamberlain war ministry, the United Kingdom government 1939–1940
• Churchill war ministry, the United Kingdom government 1940–1945
• Ministry of War Transport (United Kingdom, 1941–1946)