CSB or csb can refer to:
- California Shuttle Bus a passenger service between the San Francisco Bay Area and the Los Angeles area.
- Campo de São Bento (officially Parque Prefeito Ferraz), a public park in Niterói, Brazil.
- Canada Savings Bond
- Canadian Society for Biomechanics
- Carlos Salvador Bilardo, football coach from Argentina
- Carshalton Beeches railway station, England; National Rail station code CSB
- Cathedral School for Boys in San Francisco
- Central School of Ballet
- Cercle Sportif Brugeois an old name of Cercle Brugge
- U.S. Chemical Safety and Hazard Investigation Board
- Chen Shuibian, the former president of Taiwan
- Chitrapur Saraswat Brahmin
- Christian Service Brigade, a non-denominational Christian organization for men and boys in the United States and Canada.
- Cockayne syndrome B, a human gene mutations in which are one cause of Cockayne syndrome
- Colegio San Benito in Puerto Rico
- De La Salle-College of Saint Benilde, of Manila
- Compressed soil block, a building material
- The Collection of Computer Science Bibliographies
- Confédération Syndicale Burkinabé, the Trade Union Confederation of Burkina
- Congregation of St. Basil
- Connecticut School of Broadcasting, an American education institute.
- Crime & Security Branch (CSB), the national intelligence agency of the Garda Síochána, Ireland's police force
- Csb: warm-summer Mediterranean climate with dry summers, under Köppen climate classification
- Kashubian language (ISO 639-2 code)