Bessel may refer to:
- Bessel beam
- Bessel ellipsoid
- Bessel function in mathematics
- Bessel's inequality in mathematics
- Bessel filter, a linear filter often used in audio crossover systems
- Bessel (crater), a small lunar crater
- Bessel transform, also known as Fourier-Bessel transform or Hankel transform
- Bessel window
- Besselian date, see Epoch (astronomy)#Besselian years
- MV Bessel, a German merchant ship in service 1928-45, latterly for the Kriegsmarine
Bessel is the name of:
- Friedrich Bessel (1784–1846), German mathematician, astronomer, and systematizer of the Bessel functions
- Bessel Kok (born 1941), Dutch businessman and chess organiser