There have been two Major League Baseball players named Steve Ontiveros.
Brett Butler, actress/comedienne
Brett Butler, former Dodgers outfielder
In track and field there are two Mark Wetmores which causes some confusion.
Mark Wetmore of the University of Colorado is one of the top college track and field and cross country coaches in the US.
Mark Wetmore is one of the top track and field managers in the world.
A lot of casual track and field fans get confused because they are unaware that there are two guys in the sport with the same name.
It’s not an unusual name, but…
Two of the most popular British bands of the Eighties had drummers with the same name:
Queen and Duran Duran both had drummers named Roger Taylor.
there were two george bush’s that were both presidents within relatively close spans of each other.
Not exactly the same name, but Mark Wahlberg the actor and Mark Walberg from Antiques Roadshow.
Seriously, I think 90% of these posts have not included “unusual” names that are the same.

Ken Griffey Sr., baseball player
Ken Griffey Jr., baseball player
What do I win?
Wow, I did not know until this moment that it wasn’t Mark “y Mark” Wahlberg hosting Antiques Roadshow.
Another case of the two names being the same except for the letter “h” is the late RAF officer Peter Townsend and rock musician Peter Townshend. The military Townsend is perhaps best known for his ill-fated romance with Princess Margaret in the 1950s. When Princess Margaret died back in 2002 I did see some incorrect reports that she’d been romantically linked to The Who’s Pete Townshend. But musician Townshend was born in 1945 and so would have been in primary school at the time the princess was dating military Townsend.
Not exactly the same, but it confused me in the past (despite the generational & other obvious differences): British comic actor Peter Sellers [b. 1925] and American theater director Peter Sellars [b. 1957].
And I still have difficulty remembering how to spell them, but a pneumonic device just occurred to me: the English one is spelled with an “e,” and the American one with an “a”.
Not bad, eh?
Christopher Priest, Brit. SF writer
Christopher Priest, Am. comic book writer
For more mundane names, here are a few:
Ian Stewart, founding member of the Rolling Stones
Ian Stewart, front man for skinhead hate-rock band Skrewdriver
Larry King, retired talk show host
Larry L. King, author of The Best Little Whorehouse in Texas
Larry King, former husband of Billie Jean King
Will Smith, actor/rapper
Willi Smith, fashion designer
Unless you are referring to a device relating to the respiratory disease pneumonia, I think you mean to say mnemonic device.
Believe me, you are not the first person to make this mistake. Even the US Army Survival Manual does it.
I get excited when I see Christopher Lloyd’s name come up in TV credits, only to realise it’s that other Christopher Lloyd.
But if we held out for “really really obscure names”, we wouldn’t have a thread.
But these ARE names more unique than “Bob Johnson”, and I did get some of these mixed up before. I appreciate getting these straightened out.
I got all excited that Christopher Priest was writing Real Books after penning some of the best dialogues ever in the comic Quantum & Woody. And moments ago, I had my elation dampened.
Paul Simon, musician
Paul Simon, Senator
Paul Simon singer/songwriter
Paul Simon senator
And Will Smith, New Orleans Saints defensive end.
Back in the late 90s, a US Navy chief petty officer named Timothy McVeigh was in the news for a bit when he sued the Navy over the DADT policy. A few years earlier, of course, there was a rather more notorious Timothy McVeigh in the news.
And, in the oddly popular category of British rock musicians, there’s Mick Jones of the Clash and Mick Jones of Foreigner.
Brian May, guitarist for Queen and PhD in astrophysics
Brian May, Australian film composer, most notably for Mad Max and The Road Warrior
Tony Hawks, British comedian constantly pestered by kids who assume him to be Tony Hawk, skateboarder.