Like in Kill Bill, where Bill calls “The Bride” “Kiddo” and it turns out her name really is Kiddo. Or when Ted Lasso says to Coach (no first name) Beard “What chu talkin bout, Willis” and it turns out his name is actually Willis. Other examples?
Kramer did have a first name. Cosmo.
MacGyver did, too. Angus.
The only two examples might be the ones in the OP; the latter inspired by the former. I always thought it would be clever if (in Airplane!) Dr. Rumack’s first name was actually “Shirley” and his objection was that people were being overly familiar calling a doctor by his first name.
We didn’t find out until well into It’s Always Sunny that Mac’s full name is Ronald McDonald.
“The man with no name” actually had one.
Seems I need to clarify. I mean instances where someone has called the character by their name early on, but we do not know that it is really their name until much later. Cases where the name just isn’t mentioned at all until much later do not count for this.
That would have been great.
Not quite what the original post is asking for, but Airplane II had the courtroom scene with Andy, Buddy and Howie (“and he”, “but he” and “how he”).
From The Cheap Detective (paraphrased from memory):
JASPER: One gin sling!
LOU: Actually, I’ll just have brandy.
JASPER: No, that’s the waiter’s name - Wun Jin Sling.
The waiter then shows up with…one gin sling. Turns out his name is actually Brandy.
And a similar scene from Police Squad:
How about The Importance of Being Earnest?
IIRC, and I might not, The Handmaid’s Tale (novel) has an early list of names. The protagonist is one of them, but isn’t directly named in the novel.
It’s almost what you’re asking for:
In The Closer, Lt. Provenza’s first name is pointed never mentioned for 6 seasons. One time he was directly asked, and he said his name was “Lieutenant”. In season 7 his first name was revealed to actually be “Louis” (pronounced “Louey”), perhaps a diminutive of “Lieutenant”?
In CHINATOWN, the police lieutenant’s given name is"Lou," isn’t it?
No one knew what the J in Homer J Simpson stood for until the tenth season where we learned it stood for Jay.
BJ Hunnicutt on MASH never for sure revealed what “BJ” stood for, though he claimed it was just BJ, names after his mother Bea and his father Jay.
Hawkeye didn’t buy it, though.
In the cartoon Hey Arnold the protagonist just goes by Arnold. Since he’s a short dude, his grandfather calls him “Shortman”.
Eventually after the series ended the creator said his name was Arnold Shortman, that wasn’t just a nickname.
The Looney Tunes character now known as Gossamer originally had no name in his shorts in (checks Wikipedia) 1946 and 1952, till a 1980 short gave him the name. As far as I’m concerned, the Warner Bros. cartoon canon ended long before 1980, Chuck Jones or no Chuck Jones, and I refuse to call him that.
In Chaplin’s Modern Times, Paulette Godard is billed as “A Gamin” in the credits. However, in one shot there is a document which shows her name as “Ellen Peterson.”