BTT may refer to:

• Bhutan Time, UTC+6 hours
• Brazilian Top Team, Brazilian mixed martial arts academy
• Bettles Airport, IATA code
• Banking Transformation Toolkit, part of IBM websphere
• Banking Transaction Tax, A form of tax on cash withdrawal & other bank transactions in India
• Bayerische Theatertage, theatre festival in Germany

• Noctua pulchra
• Noctua pumicosa
• Noctua punctularis
• Noctua punctum
• Noctua ravula
• Noctua rejecta
• Noctua renago
• Noctua ridens
• Noctua roscida
• Noctua rubicunda
• Noctua ruficollis
• Noctua runica
• Noctuary (disambiguation)
• Noctuary (The Holydrug Couple album)
• Noctua sagitta
• Noctua scolopaiae
• Noctua serici
• Noctua servula
• Noctua sigma
• Noctua signa
• Noctua signum
• Noctua spectabilis
• Noctua spiralis
• Noctua spuria
• Noctua squalida