OSB may refer to:
Oberstabsbootsmann, German Navy rank Old Saybrook station in Connecticut, USA (Amtrak station code) OneSavings Bank plc, a UK registered bank, trade name Kent Reliance Operation Sovereign Borders, Australian border security operation Operation Smiling Buddha, India's first successful nuclear bomb test (1974) Oracle Service Bus, a software communication system Oriented strand board, an engineered wood
Organizations Oklahoma School for the Blind Open Source Business Alliance, sometimes known as OSB Alliance Oregon State Bar, public body that regulates the legal profession in Oregon, United States Orlando Solar Bears, ice hockey team in Florida Orquestra Sinfônica Brasileira, the Portuguese name of the Brazilian Symphony Orchestra
Christianity Order of Saint Benedict, Catholic monastic order Order of St Benedict (Anglican), Anglican monastic order Order of Saint Benedict (Orthodox), Orthodox monastic order Orthodox Study Bible, Eastern Orthodox Bible in English that includes the Septuagint