This is a disambiguation page.
It points to other pages that have similar names. If you followed a link here, please fix it to point to one of the pages listed below.
Sigma may refer to:
- Ood Sigma, an Ood (TV: Planet of the Ood)
- Sigma (planet), the home of Dr. Ivan Asimoff (COMIC: The Fabulous Idiot)
- Earl Sigma (TV: The Happiness Patrol)
- Theta Sigma, an alias of the Doctor (TV: The Armageddon Factor, The Happiness Patrol, COMIC: Flashback)
- Survey Ship Sigma, a Dalek flying saucer (COMIC: The Dalek Project)