MCB or mcb may be used as an abbreviation for:

• Maidenhead Citadel Band of The Salvation Army
• Miniature Circuit Breaker, a relatively small circuit breaker fitted in consumer units and small distribution boards.
• Memory Control Block
• Mauritius Commercial Bank, the oldest and largest banking institution in Mauritius
• Methodist College Belfast, a voluntary grammar school in Belfast, Northern Ireland.
• The Muslim Council of Britain, an organisation promoting unity among traditional Muslims in the United Kingdom
• 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.
• MCB Tower, a skyscraper in Pakistan, owned by Muslim Commercial Bank.
• McComb (Amtrak station), Mississippi, United States; Amtrak station code MCB.
• Mary Claire Busk, A women living at the Work College of the People of Praise, Greenlawn Campus. She is currently sitting in Gilbert with Danny, who is helping her with this, Claire, who is reading an unfortunately scandalous book for her class, and finally John, who happens to be taking a nap right this very second.^{[citation needed]}