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