We’ve had threads about famous people who are often confused for each other. This is a thread about famous people who have similar names . . . but who would NEVER be confused for each other . . . like:
and
Few people seem to think Aquaman was a General in the Canadian Army.
Not sure if this one fits the spirit of the OP, because people constantly mix up the names, but…
Back in the 1980s, many a pre-teen/teenage girl dragged to comic book conventions by brothers or dads were disappointed when they found out that comicdom’s Ralph Macchio is not moviedom’s Ralph Macchio.
Well, John “Ozzy” Osbourne probably doesn’t get asked about his classic play ***Look ***Back in Anger very often.
I doubt too many people mix up George Bush, Sr. and George W. Bush, but I bet they will in the future.
For those familiar with neither person:
Sir Arthur Currie, General in the Canadian Army is not to be confused with Arthur Curry, King of Atlantis.
On a similar note, it’s doubtful many people confuse Jon Stewart with John Stewart or John Stewart. Nor Guy Gardner with Guy Gardner.
Jerry Lewis and Jerry Lee Lewis
I doubt anyone would confuse Will Sampson and Wallis Simpson.
Robbie Williams and Robin Williams.
Sadly, I suspect that a lot of people don’t know the difference between Martin Luther and Martin Luther King, Jr.
Probably nobody but me mixes up Mel Gibson and Mel Brooks. I do, though.
Jerry Brown and Willie Brown.
A Black guy is mayor of SF, while a White guy is mayor of Oakland. 
Ice T and Vanilla Ice
Barack Obama and Ehud Barak.
Oh, and let’s not forget: Barack Hussein Obama and Saddam Hussein. 
True story. We got a new employee at work a few years back and his name was Robert Heinlein. Which led to this conversation:
“I know you probably get asked this a lot but are you related to the writer?”
“Which writer?”
“The writer named Robert Heinlein.”
“I didn’t know there was a writer with my name.”
He seemed serious but I can’t help thinking he was just tired of answering the question and had decided to screw around with anyone who asked him. Because how could he not have heard of Robert Heinlein? It’s not exactly a common name and the author isn’t that obscure. Even if this guy had never read a book in his life he must have been asked this question a hundred times.
John Edward and John Edwards.
Colonel Steve Austin and “Stone Cold” Steve Austin.