E8

E8 may refer to:

In mathematics:
* The E₈ Lie group in mathematics
* E₈ polytope in geometry
* E₈ manifold, a mathematical object with no smooth structure or topological triangulation
* E₈ lattice

In transport:
* E8, the IATA code for Alpi Eagles airline
* E-8 Joint STARS, a military aircraft
* EMD E8, a diesel locomotive
* HMS E8 a British E class submarine
* London Buses route E8
* Spyker E8, a Spyker Cars model

Other uses:
* E-8, an enlisted rank in the Military of the United States
* London E8, a part of the E postcode area covering Hackney Central and Dalston, London
* European route E8, part of the international E-road network, running between Tromsø, Norway and Turku, Finland