Yes, even more notable, although it does happen. Especially with all the kitchen sink/play of the week things.

And then sometimes character actors get lead parts! (One of the best, btw, being Alfred Burke in Public Eye, after having been a jobbing character actor until his mid-40s. He was also a John Silver once, too. I think I mentioned that when you asked for historicals but he had a pirate ship with a crew that included David Collings, Patrick Troughton and Stephen Greif, because why not if you can, right?)