Principal Skinner from The Simpsons, of course.
Didn’t that episode command us to never, ever mention the matter of Principal Skinner’s real identity again?
Who is John Reid?
The Lone Ranger
OK, then how about this one… Vic Vega.
There’s more of these than I would have thought.
Whatever color Michael Madsen was
Okay. How about Lamont Cranston?
OK, we’ll allow it. He was Mr. Orange in Reservoir Dogs.
Duh!!! :smack: He was Mr. Blonde in Reservoir Dogs.
Not TV and extremely obscure. Think songs.
Beauregard Rippy from Tupelo Mississippi
The Shadow knows!
Along the same lines, how about Simon Templar?
And along completely different lines, a twofer (that I admittedly had to look up to refresh my memory): Nostradamus, and Reinhold
Templar is The Saint
The others sound like mice or rats. 
The Saint
Bull Shannon and Dan Fielding. Is it a good thing or a bad thing that I didn’t have to look that up?
How about Walter Bradley?
Although they used this name occasionally, most remember him by his nickname.
Bill Briscoe
A.K.A.?
I don’t have an answer here, but how cool is it that the second and third answerers simulposted with characters from the same tv show???
Before you get lost trying to find this, let me confess that I had fused two Jerry Reed songs in my own mind: Tupelo Mississippi Flash and Guitar Man.
Call off the dogs.
TV: Lucas McCain was better known as _____?
The Rifleman. But that was just the name of the show.
He was called Lucas on the show.
Don’t know about Bill Briscoe, but it reminded me of Bill Bittinger (from a pretty obscure TV show that I loved).