|Japanese name:|| 闇の男爵|
|English name:||Knight Baron|
|First appearance:|| Manga: File 49|
Anime: Episode 43
|Appearances:|| Chapters: 11|
Night Baron (闇の男爵 Naito Baron) is a fictional character that Yusaku Kudo invented in his bestselling mystery series. Night Baron is a phantom thief who also occasionally descends to murder, but still has yet to be caught. The identity of Night Baron is currently unknown even to Shinichi. As little else is known about Yusaku's novels, Night Baron has no known nemeses or rivals. Night Baron's costume has been used multiple times to hide the identity of characters during a case. Additionally, Night Baron's name was appropriated for the name of a computer virus, which has been used by the Black Organization to protect sensitive data.
Night Baron wears a white face mask with eye-slits and a mouth curved in a twisted grin. The only visible physical features are that he is tall and thin, with straight black hair that falls just past his ears. He always wears a dark blue or black top hat, suit, and caped overcoat.
He seems very similar to Kaito Kid, but is willing to kill to avoid being captured.
 Plot overview
Night Baron's first appearance occurs when Yusaku Kudo, Yukiko Kudo, and Agasa pretend to kidnap Conan in Episode 43. Yusaku Kudo uses the Night Baron's costume as his disguise and later expresses his disappointment that Conan did not recognize the reference.
A mystery contest occurs at the Izu Princess hotel, where the participants have to guess which one among them is really the contest sponsor. The reward for the one who correctly deduces the sponsor's identity is that their stay at the hotel is free, as well as a copy of the mysterious Night Baron virus program. A costume of Night Baron is used three times. The first time, "Night Baron" pushes Conan off a high balcony into the hotel pool. Later, one of the mystery participants was in the Night Baron costume when he was pushed off a balcony and killed. Finally, another participant wears the costume to provide an alibi for the murderer.
Conan and Ai Haibara manage to obtain a disk of data on the APTX4869 poison and the Black Organization, but when Ai accesses it from an unapproved computer, the Night Baron virus destroys all the data and the computer itself.