Stephen John Thorne was a British actor of radio, film, stage, and television. He was best known for his regular BBC Radio 4 work and audiobook recordings, and for his portrayals of several Doctor Who villains, including the Time Lord Omega.

Omega is a fictional character created by Bob Baker and Dave Martin for the British science fiction television series, Doctor Who. In the context of the series, Omega is known as one of the founders of the Time Lords of the planet Gallifrey, and is a revered figure in Time Lord history together with the equally legendary Rassilon; the Third Doctor refers to him as the Time Lords' "greatest hero". Omega first appeared in the 10th anniversary story, The Three Doctors.