Australia
(Entered the War on: August 4, 1914)
Austria-Hungary
(Entered the War on: July 28, 1914)Royalty
Military Leaders
Politicians
Belgium
(Entered the War on: August 4, 1914)
Bulgaria
(Entered the War on: October 12, 1915)Royalty
Politicians
Canada
(Entered the War on: August 4, 1914)
France
(Entered the War on: August 3, 1914)Military Leaders
Politicians
Germany
(Entered the War on: August 1, 1914)Monarch
Military Leaders
Political Leaders
Others
Greece
(Entered the War on: June 29, 1917)
Italy
(Entered the War on: May 23, 1915)
Japan
(Entered the War on: August 23, 1914)
Netherlands
(Neutral Country)
New Zealand
(Entered the War on: August 4, 1914)
Ottoman Empire
(Entered the War on: October 31, 1914)
Romania
(Entered the War on: August 27, 1916)
Russia
(Entered the War on: August 1, 1914)Monarchs
Military Leaders
Political Leaders and others
Serbia
(Entered the War on: July 28, 1914)
South Africa
(Entered the War on: August 4, 1914)
United Kingdom
(Entered the War on: August 4, 1914)Royalty
Military Leaders
Political Leaders
Others
United States of America
(Entered the War on: April 6, 1917)
See also: List of people associated with World War II