There are nearly 600 hours of Star Trek. That might feel like a very random fact to open an article with but 600 hours, for one intellectual property, is an absolutely astronomical figure and puts the hours that must have gone into writing, producing, filming, and editing it comfortably into the hundreds of thousands.
And yet, despite all of that time, spanning all of those decades, only a handful of stars have ever been fired from the show. Understandably, as it's such a career-making gig with such an emphasis on recurring characters, that nobody would want to lose a character if they could help it.
Thus unlike other shows that feel like they've practically got a revolving door policy (looking at you ER), Star Trek will only fire someone as an absolute last resort. Meaning the stories behind said incidents tend to be as bizarre and strange as anything in the actual episodes themselves. Let's take a look at all the names who were forced to boldly go to the unemployment line.