| Country | Country name |
| Bolivia |  conventional long form: Plurinational State of Bolivia conventional short form: Bolivia local long form: Estado Plurinational 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 |