Why Every Classic Companion Left Doctor Who

We all know how each of the classic Doctor Who companions left the show, be it by marriage or being smeared halfway across the northern hemisphere. But companions only leave the show when the actor does, so what are the nitty gritty, behind the scenes reasons for these departures?

Whether it's new producers seeking to make their mark, an actor being under-served by their material or a desire to be more than just the voice of a robot dog, there are all sorts of reasons why actors left Doctor Who between 1963 and 1989. At the time, it would often be stated that the departing actor was looking for new opportunities, but with the benefit of decades worth of convention appearances, autobiographies and DVD commentaries, more details have come to light about many of these departures.

Before we start, it's worth establishing what we mean by companion. For the benefits of this list, we'll be focusing on named characters who travelled in the TARDIS for a considerable amount of time, or - in the case of the brave boys of UNIT - held semi-regular supporting roles. 

So for the avoidance of doubt, yes Sara Kingdom absolutely counts.

The Doctor's first companion was, of course, his granddaughter Susan. Played by Carole Ann Ford, Susan was the titular Unearthly Child that kicked off the next 60+ years of adventures through time and space. 

Unfortunately for Carole Ann Ford, she was rarely afforded the chance to play up Susan's unearthly qualities, leading to frustrations for the actress. Speaking to the Radio Times in 2023, Ford reflected that all the "interesting" aspects of the character "were all eliminated after the first episode."

It was this frustration that led to Carole Ann Ford choosing not renew her contract after the completion of The Dalek Invasion of Earth. Interestingly, David Brunt's book The Doctor Who Production Diary: The Hartnell Years suggests that it might have been a mutual decision. Verity Lambert is quoted in official correspondence saying that the production team has "no desire" to renew Ford's contract!