Not the same last name, but there’s Harry the wizard from Harry Potter, and there’s Harry the wizard from the Dresden Files.
There was a Michael Bolton in Office Space, and…
Nevermind.
How about Same name, Same director, Different character?
François Pignon is the name of a character that turns up in at least half a dozen films directed by Francis Veber - but it’s a different actor more or less every time, and certainly not the same character in all of them.
Similarly, Neil Simon mentions a character called **Felix Unger[/.B] in Come Blow Your Horn. This is clearly not the OCD neatnik of the same name from The Odd Couple.
I suspect that “Felix Unger” came from a inside joke between Simon and his circle, as a name that could go to the initials “F.U.” Simon uses the gag at one point in The Odd Couple :
Oscar: Don’t leave notes on my pillow. I hate notes on my pillow. This morning I found this – “Don’t forget to pick up Corn Flakes – F.U.” It took me fifteen minutes to figure out that “F.U.” meant “Felix Unger”!
I don’t know why I remember this, but an Agatha Christie short story featured a character named James Bond, long before Ian Flemming began writing about 007.
Van Bueren’s Tom and Jerry bore little resemblance to the cat and mouse.
The name of the murder victim in Action #1, published in June, 1938(first appearance of Superman) was Jack Kennedy.
That was 25 years before President John (Jack) Kennedy was murdered.
Wasn’t the hooker in DS9 Leela too? they called her a dabo girl.
The pairing of “Tom” and “Jerry” goes back at least to 1821, when Pierce Egan began publishing a periodical called “Life in London or, the Day and Night Scenes of Jerry Hawthorn, esq., and his elegant friend, Corinthian Tom, accompanied by Bob Logic, the Oxonian, in their rambles and Sprees through the Metropolis.” It was adapted into the stage play “Tom and Jerry, Or Life in London,” which ran in London and New York. Egan also created a drink (a variant of egg nog) to publicize his characters.
Not sure if this counts, but in “Race to Witch Mountain” there is a scene where the reporter signing off says her name is Natalie Gann. The actress playing the reporter (Meredith Salenger) starred in another Disney movie called “The Journey of Natty Gann.” If memory serves correctly this is not the first time Disney has done this.
No, that was Leeta, played by the delightful Chase Masterson.
This really doesn’t count but…
Count Dracula the suave seductive European played by Lugosi, Langella, Jordan, Oldman et al
Count Dracula the hook-nosed European blood-drinking rapist played by… maybe Max Schreck and written about by Bram Stoker.
Similar to this is the name of one of the criminals in Fredric Brown’s first novel, The Fabulous Clipjoint – “Dutch” Reagan. “Dutch” was Ronald Reagan’s nickname from his college days, and was still used by his closest and oldest friends during his presidency.
Neither of these exactly fit the OP’s criteria, since one of the named people is an actual president, but they are interesting coincidences.
Not exactly in the OP, but John Cleese’s character in A Fish Called Wanda was Archie Leach, which was Cary Grant’s real name. (And done intentionally of course)
I’ll allow it. 
If you need it, Cary Grant’s character in HIS GIRL FRIDAY isn’t named Archie Leach, but mentions a character with that name.
Newsradio and 24 both had characters named Lisa Miller. And both actresses playing Lisa Millers went on to play doctors on ER.
There are two completely different professional wrestlers (one a man in GWF and WCW, one a woman in TNA) who have used the character name Awesome Kong.
Diagnosis Murder and Grey’s Anatomy both have Mark Slone characters.
Stan Grossman is a character in both Fargo and Little Miss Sunshine.
So…this is okay, then? I don’t know if I have a snow ball’s chance in hell of ever publishing the novel I’m working on (the most immediate huddle is that finishing stories is not my strong suit) but I worried a little because my protagonist apparently shares the name of a reoccurring character played by Yasmine Bleeth on Nash Bridges. I couldn’t think of any instances with two characters sharing a name, so it’s nice to see a list of them.
There were at least 3 Tanner families on 80s Sitcoms.
Frank Black appears a lot - a Pixie, the main character on Millennium, and I’m sure I’ve seen that name pop up in other places too.