ZN or Zn may stand for:
- Air Bourbon IATA airline designator
- Azimuth, a mathematical concept defined as the angle between a reference plane and a point
- Zenith, the direction pointing directly above a particular location
- Zettanewton, an SI unit of force
- Ziehl-Neelsen stain, a special bacteriological stain used to identify acid-fast organisms
- ZiffNet, a small, diverse set of online forums and information services, now called ZDNet
- Zinc, a metal
- Zombie Nation (band), an elektro artist from Germany
- Zontanoi Nekroi, a battle rap group from Greece
- Zn cyclic group
- ℤn integers modulo n (Modular arithmetic)