Named by the Adaptation

There are a lot of characters with No Name Given out there. This trope is where an adaptation is made of the character's story and the character is given a name. This can range from the main character to secondary characters as well. The character may have become an Ascended Extra in the adaptation. It often serves to make the character seem more relatable though whether or not this works is up for debate. Another variation is where the character doesn't have a last name and is given one in the adaptation. Doesn't apply to characters whose names are changed in the adaptation. Compare Canon Name which is about linear installments.

Anime & Manga

 * In the anime of Ranma ½, Hiroshi, Daisuke, Yuka, and Sayuri are given names.
 * There's a few cases in Dragon Ball, several of which ended up making their way back to the manga at a later point, like Shuu, Mai and Suno. Interestingly, Shuu was actually named "Soba" in his first manga appearance and became Shuu in later ones after it was used in the anime and Suno's name was only used in the manga when she made a single panel cameo a few hundred chapters after her main appearance.

Comic Books

 * The Leprechaun was given a name in the short lived comic spin off series.

Film

 * In the original novel The Witches the protagonist isn't named (he's the narrator), his grandmother is called "Grandmamma" by him and the Grand High Witch is referred to as...well the Grand High Witch. In the film version the boy is called Luke, his grandmother Helga and the Grand High Witch is called Eva Ernst though it's never said if this is her real name or an alias she uses when checking into the hotel.
 * In the X-Men comics, Rogue's real name is unknown. In the live action films she is given the name Marie D'Ancanto.
 * The Joker's name has never been revealed in the comics but in Tim Burton's Batman he is named Jack Napier.
 * In the film version of 12 Angry Men where none of the twelve jurors are named, two are given last names in the epilogue.
 * The unnamed protagonist of The Time Machine was named George in the 1960s film and Alexander Hartdegen in the 2002 film.
 * In Voyage of the Dawn Treader Ramandu's daughter is unnamed but is called Lilliandil in the live action film version.
 * Also in The Lion, The Witch and the Wardrobe Lucy says her mother's name is Helen when it was never revealed in the books. Helen is Georgie Henley's mother's name and it was ad libbed by her at the last minute.
 * And the Witch's dwarf servant is named "Ginabrik."
 * A variation comes with Bram Stokers Dracula where Dracula's real name was never revealed in the book but the film makes him into the vampirised corpse of Vlad the Impaler from history.
 * The unnamed narrator/protagonist of a series of spy novels by Len Deighton became Harry Palmer in the film versions.
 * The Prince of Persia was named Dastan in the film based on the "Sands of Time" trilogy. The games never gave him a name beyond 'the Prince'.
 * In Danny, the Champion of the World, Danny's surname is not revealed. In the film, it's Smith. His father, entirely unnamed in the book, is named William in the film.
 * The unnamed boy who narrates The Cat in the Hat is named Conrad in The Film of the Book, Dick in the "Cat in the Hat's Learning Library" series of books, and Nick in The Cat in the Hat Knows a Lot About That!! (the latter gives him a Race Lift, inexplicably enough). The fish, meanwhile, gets the name Carlos K. Krinklebein in the TV special.
 * The 2010 Alice in Wonderland movie gives proper names to most characters that were only known by nicknames in Carroll's book such as the caterpillar being called Absolon.
 * In Star Trek 2009 Uhura is given the first name Nyota. Note this name was Fanon for a long time before the film came out.
 * In The Tomorrow Series, Lee is the only main character not given a surname. In the film, he's credited as "Lee Takkam".
 * The unnamed protagonist of the Doom video games is Flynn Taggart in the spin-off novels and John Grimm in the movie.
 * In Harry Potter and The Goblet of Fire, Lord Voldemort's deceased grandparents are not given first names. In the movie version, their gravestone identifies them as Thomas and Mary Riddle. Apparently, the filmmakers got these names from J. K. Rowling, making this weirdly double as Word of God.
 * This applies to a building instead of a character, but the books never give a name to the orphanage Voldemort lived in as a child. In a flashback from the sixth film, the sign out front reads "Wool's Orphanage". It's unclear whether this name came from Rowling or if the filmmakers invented it.
 * The Hogwarts lake is never named in the books. The films call it "the Black Lake" and this name is recognized by the Harry Potter Wiki.
 * Disney's Mary Poppins names the mother Winifred Banks. Originally, the film was going to call her "Cynthia", but P. L. Travers thought that didn't "sound English enough".
 * Dracula's brides didn't have names in the book. Van Helsing expands their role and names them each Aleera, Verona and Marishka.
 * Every single character in Snow White a Tale of Terror.

Literature

 * The Doctor Who spin-off novels have given names to several Time Lords previously only known by nicknames: the Master (Koschei), the Rani (Ushas), the Meddling Monk (Mortimus), and the War Chief (Magnus). (The last of these is a continuity patch: Doctor Who Magazine once ran a comic strip with a young First Doctor [refered to as "Thete"] arguing with a contemporary named Magnus. At the time this was clearly meant to be the Master, but when the books revealed the Master's real name as Koschei, Magnus had to be someone else...)

Live Action TV

 * Faith from Buffy the Vampire Slayer never had a last name in the TV series but was given Lehane as a last name in the role playing game. It's now treated as canon. Kendra was also given Young as a last name.
 * Similarly, Spike received his surname "Pratt" in IDW's comics.
 * In The Worst Witch books, Maud's last name wasn't revealed until "The Worst Witch All At Sea" where she is called Maud Spellbody. The TV series gave her the last name "Moonshine". Drucilla was also given the last name "Paddock".
 * All the teachers are also given first names that they didn't have in the book. Miss Cackle's becomes Amelia, Miss Hardbroom is Constance, Miss Bat is Davina and Miss Drill is Imogen.
 * The TV adaption of Dashiell Hammett's The Dain Curse gave the previously unnamed "Continental Op" the moniker of Hamilton Nash. The name was described as Dashiell Hammett "spelled sideways."

Theatre

 * Frank R. Stockton's short story "The Lady or the Tiger?" was a Nameless Narrative. When it was adapted into the second act of The Apple Tree, the principal characters gained names: King Arik, his daughter Princess Barbara, her lover Captain Sanjar, and the lady behind one of the doors, Nadjira. The Passionella act of The Apple Tree also gave the name of Ella's old employer, Mr. Fallible, and had Flip finally reveal his real name, George L. Brown.
 * In the musical version of Candide, Cunegonde's brother, who doesn't have a name in the novel, is called Maximilian. (The musical also gives him slightly more of a personality: he is both gay and narcissistic!)

Western Animation

 * Scarface's mate doesn't have a name in the original book versions of The Animals of Farthing Wood while in the TV series she is called Lady Blue.
 * The Little Red-Haired Girl in Peanuts is called Heather in one of the animated specials.
 * In the book A Day with Wilbur Robinson, Wilbur's friend, who narrates the story, goes unnamed. When expanded into Meet the Robinsons, he is given the name Lewis.
 * The Disney Animated Canon has named several Fairy Tale characters who did not have names originally:
 * The dwarves in Snow White and The Seven Dwarfs.
 * The stepmother and stepsisters in Cinderella.
 * Everyone in The Little Mermaid. The original only identifies the characters as "the little mermaid", "the sea witch", "the prince", and so forth.
 * Beauty and the Beast is an odd case. The heroine was originally referred to as "Beauty". However, "belle" is the French word for "beauty", so the original French versions would call her "belle", but not as her name. Conveniently, it happens that "Belle" is a real first name, so Disney made it the character's actual name. Additionally, Beauty/Belle's father is given the name "Maurice".
 * Princess Jasmine in Aladdin. Interestingly, Disney was not the first to use that name. Aladdin's princess was first called "Jasmine" in an obscure '50s film called Aladdin and His Lamp. Disney also gave the Grand Vizier character the name "Jafar".
 * In the animated movie and TV show adaptations of Curious George, the Man in the Yellow Hat is named Ted.
 * The U.S. Acres cartoons from Garfield and Friends gave the names Mort, Gort, and Wart to Orson's bullying brothers who had originally only appeared in the first three weeks of the original comic strip.
 * All of the locomotives in the animated version of The Little Engine That Could. The Little Blue Engine is named Tilly, the Broken-Down Engine Georgia, the Shiny New Engine Farnsworth, the Big Strong Engine Pete, and the Rusty Old Engine Jebediah.