E0

E0 or E00 can refer to :
* ε₀, in mathematics, the smallest transfinite ordinal number
* ε₀, in physics, the fundamental vacuum permittivity constant
* E0 (cipher), a cipher used in the Bluetooth protocol
* E0 (robot), a 1986 humanoid robot by Honda

and also :
* E0, the digital carrier for audio, specified in G.703
* Eos Airlines IATA code
* E00 : Cretinism ICD-10 code