| Country | Country name |
| Bolivia | conventional long form: Republic of Bolivia conventional short form: Bolivia local long form: Republica de Bolivia local short form: Bolivia |
| Bosnia and Herzegovina | conventional long form: none conventional short form: Bosnia and Herzegovina local long form: none local short form: Bosna i Hercegovina former: People's Republic of Bosnia and Herzegovina, Socialist Republic of Bosnia and Herzegovina |
| Botswana | conventional long form: Republic of Botswana conventional short form: Botswana local long form: Republic of Botswana local short form: Botswana former: Bechuanaland |
| Bouvet Island | conventional long form: none conventional short form: Bouvet Island |
| Brazil | conventional long form: Federative Republic of Brazil conventional short form: Brazil local long form: Republica Federativa do Brasil local short form: Brasil |
| British Indian Ocean Territory | conventional long form: British Indian Ocean Territory conventional short form: none abbreviation: BIOT |
| British Virgin Islands | conventional long form: none conventional short form: British Virgin Islands abbreviation: BVI |
| Brunei | conventional long form: Brunei Darussalam conventional short form: Brunei local long form: Negara Brunei Darussalam local short form: Brunei |
| Bulgaria | conventional long form: Republic of Bulgaria conventional short form: Bulgaria local long form: Republika Balgariya local short form: Balgariya |
| Burkina Faso | conventional long form: none conventional short form: Burkina Faso local long form: none local short form: Burkina Faso former: Upper Volta, Republic of Upper Volta |
| Burma | conventional long form: Union of Burma conventional short form: Burma local long form: Pyidaungzu Myanma Naingngandaw (translated by the US Government as Union of Myanma and by the Burmese as Union of Myanmar) local short form: Myanma Naingngandaw former: Socialist Republic of the Union of Burma note: since 1989 the military authorities in Burma have promoted the name Myanmar as a conventional name for their state; this decision was not approved by any sitting legislature in Burma, and the US Government did not adopt the name, which is a derivative of the Burmese short-form name Myanma Naingngandaw |
| Burundi | conventional long form: Republic of Burundi conventional short form: Burundi local long form: Republique du Burundi/Republika y'u Burundi local short form: Burundi former: Urundi |
| Cambodia | conventional long form: Kingdom of Cambodia conventional short form: Cambodia local long form: Preahreacheanachakr Kampuchea (phonetic pronunciation) local short form: Kampuchea former: Khmer Republic, Democratic Kampuchea, People's Republic of Kampuchea, State of Cambodia |
| Cameroon | conventional long form: Republic of Cameroon conventional short form: Cameroon local long form: Republique du Cameroun/Republic of Cameroon local short form: Cameroun/Cameroon former: French Cameroon, British Cameroon, Federal Republic of Cameroon, United Republic of Cameroon |
| Canada | conventional long form: none conventional short form: Canada |
| Cape Verde | conventional long form: Republic of Cape Verde conventional short form: Cape Verde local long form: Republica de Cabo Verde local short form: Cabo Verde |
| Cayman Islands | conventional long form: none conventional short form: Cayman Islands |
| Central African Republic | conventional long form: Central African Republic conventional short form: none local long form: Republique Centrafricaine local short form: none former: Ubangi-Shari, Central African Empire abbreviation: CAR |
| Chad | conventional long form: Republic of Chad conventional short form: Chad local long form: Republique du Tchad/Jumhuriyat Tshad local short form: Tchad/Tshad |
| Chile | conventional long form: Republic of Chile conventional short form: Chile local long form: Republica de Chile local short form: Chile |
| China | conventional long form: People's Republic of China conventional short form: China local long form: Zhonghua Renmin Gongheguo local short form: Zhongguo abbreviation: PRC |
| Christmas Island | conventional long form: Territory of Christmas Island conventional short form: Christmas Island |
| Clipperton Island | conventional long form: none conventional short form: Clipperton Island local long form: none local short form: Ile Clipperton former: sometimes called Ile de la Passion |
| Cocos (Keeling) Islands | conventional long form: Territory of Cocos (Keeling) Islands conventional short form: Cocos (Keeling) Islands |