- Blue Sky justifies this with Wheatley. His Brain Uploading caused him to forget most of his previous life, including his full name. Caroline later on reveals that his full name is Stephen Wheatley.
- Because I'm Not Popular I'll Try to Go Out with a Hero has Venom only refer to Peter by his last name.
- Examples from the Calvinverse:
- Despair's Last Resort: Chiyo Ueda, Arata Miyazaki, and Kazumi Katsuya all do this. Chiyo does it out of politeness (and uses "Ms." or "Mr." on most people), while the other two out of rudeness. Chiyo makes an exception for her Childhood Friend Kumiko. Shortly before Shizuka's execution, Kazumi starts referring to her by first name. Arata calls Takara by her first name after she figures out his crime, but it doesn't last long since he gets executed.
- In the Gensokyo 20XX series, we have this to somewhat the case with Mokou who is nicknamed "Huzi", being that her last name, Fujiwara, is alternatively pronounced and spelled Huziwara, leading for her nickname to be Huzi and she is usually referred to as such. Apparently, an age-regressed Reimu thinks her first name is her last name.
- At least one Mass Effect fic justifies Commander Shepard only being called by their rank or last name by explaining that no one (Shepard included) actually knows their first name.
- Superwomen of Eva 2: Lone Heir of Krypton: Section Two Chief Chiron is only known by his last name. Nobody refers to him by his name.
- This Bites!: Partially due to having a different naming convention, all of the Straw Hats call Cross by his last name instead of Jeremiah. This is also on account of Cross much preferring to be referred to as his last name instead of Jeremiah, or any variation thereof.
- Chrysalis Visits The Hague: The lawyer Alexander Estermann keeps this going, much to the point that the narration sticks to just referring to him as Estermann, reflecting his somewhat stuck-up professionalistic nature.
- Rei tells Kaworu to call her by her last name in chapter 11 of Advice and Trust since she lost all her memories of him after dying in the battle against the 16th angel (her latest memory backup having been just before meeting him).
- In Where Talent Goes To Die, most of the cast addresses each other this way, since they're Japanese high schoolers who have only just met each othernote . Mitamura in particular insists on being called "Mitamura-san," since she addresses all other classmates by their last names and "-san."
- As in canon, most characters in Skyhold Academy Yearbook address Marian Hawke by her surname only. Her sister Bethany, her close friend Cassandra, and her colleague Cullen are the only ones ever seen to call her by her first name.
- In Neither a Bird nor a Plane, it's Deku!, only a handful of characters have addressed Izuku by his given name: his parents, Firestorm, and Alexis Luthor. The rest address him as "Midoriya" except for Bakugou, who calls him "Deku". This is particularly noticeable when Izuku is conversing with his parents, as he's still referred to in the narration as "Midoriya" even as his parents are referred to by their given names.
- RainbowDoubleDash's Lunaverse: In "Nightmares Yet to Come", Midnight tends to refer to ponies by their second name exclusively (though apparently if they have a title, she'll use that as well). Her introduction mentions she does this to Trixie, who hates being called by her last name of Lulamoon due to childhood taunting, despite many attempts on Trixie's part to get her to do otherwise. So far, what she does with ponies who have only one name (like Applejack, or Raindrops) is unclear.
Last Name Basis / Fan Fic