MCB or mcb may be used as an abbreviation for:

• Maidenhead Citadel Band of The Salvation Army
• Mauritius Commercial Bank, the oldest and largest banking institution in Mauritius
• MCB Tower, a skyscraper in Pakistan, owned by Muslim Commercial Bank.
• McComb (Amtrak station), Mississippi, United States; Amtrak station code MCB.
• Miniature Circuit Breaker, a relatively small circuit breaker fitted in consumer units and small distribution boards.
• Memory Control Block
• Methodist College Belfast, a voluntary grammar school in Belfast, Northern Ireland.
• Molecular and Cellular Biology, the subject of either molecular biology, or cellular biology.
• Molecular and Cellular Biology (journal), a scientific journal published by the American Society for Microbiology
• Monochlorobenzene, an aromatic organic compound
• Music Colony Bi-weekly, a music magazine in Hong Kong.
• Muslim Commercial Bank, a network of bank in Pakistan.
• The Muslim Council of Britain, an organisation promoting unity among traditional Muslims in the United Kingdom