13B may refer to:
- 13B: Fear Has a New Address or Yavarum Nalam, a 2009 Indian horror film
- Boron-13 (<sup>13</sup>B), an isotope of boron
- A Mazda Wankel engine
- A Toyota B engine
- Section 13b of the Securities Exchange Act of 1934
See also
- B13 (disambiguation)