BU, Bu and variations may refer to:
Buddhism (, US: ) is the world's fourth-largest religion with over 520 million followers, or over 7% of the global population, known as Buddhists.
Bulgaria ( (listen); Bulgarian: България, romanized: Bǎlgariya), officially the Republic of Bulgaria (Bulgarian: Република България, romanized: Republika Bǎlgariya, IPA: [rɛˈpublikɐ bɐɫˈɡarijɐ]), is a country in Southeast Europe.
Budapest (, Hungarian pronunciation: [ˈbudɒpɛʃt]) is the capital and the most populous city of Hungary, and the tenth-largest city in the European Union by population within city limits.
Buenos Aires ( or ; Spanish pronunciation: [ˈbwenos ˈaiɾes]) is the capital and largest city of Argentina.
Bupropion, sold under the brand names Wellbutrin and Zyban among others, is a medication primarily used to treat major depressive disorder and to support stopping smoking.
Buzz Aldrin (; born Edwin Eugene Aldrin Jr.; January 20, 1930) is an American engineer and a former astronaut and fighter pilot.
Buffalo is the second largest city in the U.S. state of New York and the largest city in Upstate New York.