List of sovereign states in 1918

A

• Afghanistan - Emirate of Afghanistan
•  Andorra - Principality of Andorra
•  Argentina - Argentine Republic
• Republic of Armenia - (from May 28)
•  Australia - Commonwealth of Australia
• Asir - Emirate of Asir
• Asir, Upper - Emirate of Upper Asir
• Austria
  •  Austria-Hungary - Austro-Hungarian Empire (to November 12)
  • German-Austria - Republic of German Austria (from November 12)
• Azerbaijan - Azerbaijan Democratic Republic (from May 28)

B

•  Belgium - Kingdom of Belgium
•  Bolivia - Republic of Bolivia
•  Brazil - Republic of the United States of Brazil
•  Bulgaria - Kingdom of Bulgaria

C

•  Canada - Dominion of Canada
•  Chile - Republic of Chile
•  China - Republic of China
•  Colombia - Republic of Colombia
•  Costa Rica - Republic of Costa Rica
•  Cuba - Republic of Cuba
• Czechoslovakia - Czecho-Slovak Republic (from 28 October)

D

•  Denmark - Kingdom of Denmark
•  Dominican Republic

E

•  Ecuador - Republic of Ecuador
•  El Salvador - Republic of El Salvador
•  Estonia - Republic of Estonia (from February 24)
•  Ethiopia - Ethiopian Empire

F

• France - French Republic

G

• Georgia - Democratic Republic of Georgia (from May 26)
• Germany
  • German Empire (to November 9)
  • German Reich (Weimar Republic from November 9)
• Greece - Kingdom of Greece
•  Guatemala - Republic of Guatemala

H

• Ha'il - Emirate of Ha'il
• Haiti - Republic of Haiti
• Hejaz - Kingdom of Hejaz
• Honduras - Republic of Honduras
• Hungary - Hungarian Democratic Republic (from November 16)

I

•  Italy – Kingdom of Italy

J

•  Japan - Empire of Japan

L

• Latvia (Disputed between two governments)
  • Republic of Latvia (from November 18)
  • Latvian Socialist Soviet Republic (from December 17)
•  Liberia - Republic of Liberia
•  Liechtenstein - Principality of Liechtenstein
•  Lithuania - Republic of Lithuania (from November 2)

M

•  Mexico - United Mexican States
•  Monaco - Principality of Monaco

N

• Nejd - Emirate of Nejd and Hasa
• Nepal - Kingdom of Nepal
•  Newfoundland - Dominion of Newfoundland
• New Zealand - Dominion of New Zealand
•  Netherlands - Kingdom of the Netherlands
•  Nicaragua - Republic of Nicaragua
•  Norway - Kingdom of Norway

O

• Ottoman Empire - Sublime Ottoman State

P

• Panama - Republic of Panama
•  Paraguay - Republic of Paraguay
• Persia - Persian Empire
•  Peru - Peruvian Republic
• Poland - Republic of Poland (from November 11)
•  Portugal - Portuguese Republic

R

•  Romania - Kingdom of Romania
• → →  Russia
  • Russian Soviet Republic (to January 28)
  • Russian Socialist Federative Soviet Republic (from January 28)

For the Russian Democratic Federative Republic, see Other states

S

• San Marino - Most Serene Republic of San Marino
• Yugoslavia
  • Slovenes, Croats and Serbs - State of Slovenes, Croats and Serbs (from October 28 to December 1)
  •  Serbs, Croats and Slovenes - Kingdom of Serbs, Croats, and Slovenes (from December 1)
•  Siam - Kingdom of Siam
•  South Africa - Union of South Africa
• Spain - Kingdom of Spain
•  Sweden - Kingdom of Sweden
•   Switzerland - Swiss Confederation

T

• Transcaucasia - Transcaucasian Democratic Federative Republic (from February 24 to May 28)

U

•  United Kingdom - United Kingdom of Great Britain and Ireland
•  United States - United States of America
•  Uruguay - Eastern Republic of Uruguay

V

• Venezuela - United States of Venezuela

Y

• Yemen - Mutawakkilite Kingdom of Yemen (from November 1)