E-123 Omega may refer to:
- E-123 Omega, the character from the Sonic the Hedgehog video game series.
- E-123 Omega (Archie), the character from the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics.
- E-123 Omega (Pre-Super Genesis Wave), the version of Omega from before the Super Genesis Wave.
- E-123 Omega (CoroCoro), the character from the The Jet Black Hedgehog: Shadow the Hedgehog manga series created by CoroCoro Comic.