B16 or B-16 may refer to:
- B16 (New York City bus) serving Brooklyn
- HLA-B16, an HLA - B serotype
- Honda B16 engine
- Volvo B16 engine
- LNER Class B16, a class of British steam locomotives
- Martin XB-16, a proposed bomber aircraft
- B16 melanoma, a cell line
- Boron-16 (B-16 or <sup>16</sup>B), an isotope of boron
- One of the ECO codes for the Caro–Kann Defence in chess
- Pope Benedict XVI
- Bundesstraße 16, federal highway in Germany
- 16 amp, type B – a standard circuit breaker current rating
- B16 Standardization of Valves, Flanges, Fittings, and Gaskets - ASME committee and specification group.