A recent HowToGeek post called out Deep Roy as being the only actor to have appeared in all of the Star Wars, Star Trek, and Doctor Who franchises. A comment on that post mentions that Simon Pegg has also played characters in all those franchises but, since his Star Wars role was a voice-over, I believe this stretches the definition of "appeared" just a bit.
Another comment poses this question though, which I'm interested in having answered here:
Ah but are there any actors who have appeared in all three of the big Star
****franchises? Star Trek, Star Wars, and Stargate.
For the purposes of this question, "appeared" should be taken as "had an on-screen presence". That is to say, voice-overs don't count. Photographs or casual references made by other characters do not count either. The actor must have actually had a role, and been physically present in front of the camera, in a movie or TV production associated with each of the three
Star-* franchises: Star Wars, Star Trek, and Stargate.
Are there any actors who fit this description?