List of characters who know Conan's identity
Over the course of the series, 22 characters have come to know that Conan Edogawa is actually Shinichi Kudo (11 of which are not manga canon). In addition, Ran Mouri has noticed similarities between the two and Kogoro Mouri, Wataru Takagi and Rei Furuya have shown signs of doubting that Conan is just "very smart". This should not be confused with the people who know Conan is the puppeteer behind Sleeping Kogoro.
In their respective categories, characters are listed by the order they came to discover (or become suspicious of) Conan's identity.
So far eleven people have learned Conan's true identity is Shinichi in the manga canon. Four were told the truth, six discovered it for themselves. How the remaining one became aware of this is unconfirmed.
 Hiroshi Agasa
Professor Agasa found out in Volume 1, the very beginning of the series during the second chapter. Shortly after Shinichi had been shrunk, he went back to his home, but was unable to enter his house due to his shrunken state. Professor Agasa had soon appeared and Shinichi revealed his identity, although he didn't believe Shinichi even after he displayed knowledge that only Shinichi would know. It wasn't until did Shinichi display his deductions and intelligence did Professor Agasa realize that the young child really was Shinichi Kudo. 
 Akemi Miyano (Deceased)
 The Kudo Couple
 Heiji Hattori
Heiji Hattori found out in Volume 13. Originally when he first met Conan, he didn't realize the truth as he was blinded by his competitive nature to beat Shinichi and prove he was the better detective. During their second encounter in the Holmes Freak Murder Case, he started to realize the similiarites between Conan and Shinchi as well as the fact that neither of them were in the same room together during their first meeting. Due to this, Heiji came to realize that the young child Conan Edogawa was in fact the Famous High School Detective Shinichi Kudo. However, he lacked proof until he secretly witnessed Conan speaking in Heiji's voice after Heiji was knocked unconsciousness by the Stun-Gun Wristwatch. He secretly regained consciousness and witnessed Conan solving the case in his voice and confronted him shortly thereafter. While Conan still refused his claims, Heiji threatened to expose his identity to Ran and thus Conan had quickly confessed the truth of his identity. 
 Ai Haibara/Shiho Miyano
Ai Haibara's deduction of that was mentioned in Volume 18, after knowing Shinichi's clothes from his childhood had somehow disappeared from his house and that APTX4869 had de-aged one mouse during trials.
Vermouth realized similarities between Shinichi (when he was young) and Conan. She also chose not to betray Shinichi to the Black Organization, most likely because he and Ran saved her when she was disguised as a serial killer in New York.
 Eisuke Hondou
Eisuke Hondou revealed his awareness of Conan's true idenitiy in Volume 60. Originally when he began investigating the whereabouts of his sister, he was still unaware that Rena Mizunashi was his sister or the fact she is an agent of the CIA. When she disappeared, he began investigating and believed that Kogoro was responsible behind her disappearance since he was the last person to see her. However when he began further investigating Kogoro, it lead to him discovering Conan Edogawa is really Shinichi Kudo. He realised that Kogoro's skills as a detective were different before he began "Sleeping Kogoro" and noticed that Conan was always by his side whenever he was solving a case as well as the fact that Shinichi had taken a leave of absence from school around the exact same time.
Upon these discoveries, Eisuke discovered Conan Edogawa was really Shinichi Kudo, but still didn't know how he became small. This reveals that even before they first met, Eisuke knew all along who Conan really was. When he first met Conan, Eisuke purposely fell into him, knocking off his glasses. Then acting as if he couldn't see, he called Conan, Detective Mouri. Later after finding his sister and learning the circumstances, Eisuke revealed his desire to go to America to join the CIA to follow in the footsteps of his father and sister. Eisuke also confesses to Conan that he is in love with Ran and desires to bring her with him to America, but wants to ask for Shinichi's permission after learning that Shinichi and Ran are in love. Due to this, Conan reveals himself as Shinichi Kudo, refusing Eisuke's request and Eisuke then revealed this truly confirms his suspicions and confesses to knowing Conan's true identity all along.
 Subaru Okiya/Shuichi Akai
Subaru Okiya (officially revealed to be Shuichi Akai in File 898) obtained proof of Conan's identity when he caught Conan pretending to be Shinichi over the phone. Based on some of the questions he asked Ran, he may have deduced Conan was Shinichi very soon after he moved into the Kudo house, but had lacked absolute proof up until the phone incident. Since finding out the truth, he teases Conan and has on occasion confronted him regarding his identity, but doesn't further press the issue until Conan is ready to reveal the truth himself. However, while Conan still refuses to speak of his identity, it's revealed he has already realised that Shuichi Akai knows he is Shinichi Kudo.
 Masumi Sera
Sera seems to have known Conan was Shinichi before they first met recently. Masumi remembers Shinichi from some meeting they had in the past and has been since trying to encourage Conan to remember where he met her. In "Conan vs. Heiji, Deduction Battle Between the Detectives of the East and West" episode, it's confirmed that Sera knows when she thinks "Now we already know who's the winner" while looking towards Conan that thinking about the case, referring him as "Shinichi". Also during Deduction Showdown at the Haunted Hotel, she purposely made a mistake in her deductions so she could test Conan's skills and make him solve the case using Shinichi's voice.
 Mary Sera
In Volume 90 (Soul Detective Murder Case), Mary told Masumi that Conan is no longer the same person that she and Masumi met 10 years ago. This implies that she is aware that Conan is Shinichi.
 Kaitou Kid/Kaito Kuroba
Kaitou Kid (also known as Phantom Thief Kid) becomes aware of Conan's true identity in The Last Wizard of the Century. While disguised as Ninzaburo Shiratori, Kid had bugged the phones on the Suzuki Financial Group's ship and therefore heard all of the conversation between Conan and Agasa on the phone. Not realizing they were being listened to, Agasa continued to refer to Conan as "Shinichi" on the phone as he normally does. It is assumed that afterwards Kid put two and two together. Kid's knowledge of Conan being Shinichi is confirmed in The Lost Ship in the Sky. Kid's knowledge of Conan's identity has not been stated in the manga and has not been confirmed by Gosho Aoyama to be canon, although in the manga Kid is definitely aware that Conan is no mere child.
 Hiroki Sawada (Deceased)
Hiroki Sawada in The Phantom of Baker Street; how he knew that was not given, though it was most likely through the DNA Query Program.
 Hajime Kindaichi
 Lupin III Cast
In the TV Special Lupin III vs. Detective Conan, the famous gentleman thief named Lupin III and his associates Jigen, Fujiko, and Goemon, through some means discover Conan's true identity and help him sneak back into Japan after traveling to the country Vespania (Conan would've needed a passport to return home, but his passport was for Shinichi Kudo).
 Irish (Deceased)
In the 13th movie, The Raven Chaser, Black Organization member Irish discovers Conan's secret identity. However, instead of revealing it to the Organization, he decides to use that to gain more power with the boss, because of an old grudge he has with Gin for killing Pisco, his mentor, without orders to do so. He is shot to death by Chianti before he can do anything.
 Alan Smithee (Deceased)
In Lupin III vs. Detective Conan: The Movie, Conan revealed his true name to Alan. Alan died shortly after that.
 Konosuke Jii
In the 19th movie, Sunflowers of Inferno, Konosuke was explained to know Conan's true identity.
 Tokujiro Nagai
Tokujiro Nagai (長井 徳次郎 Nagai Tokujirō), age 72, is the Nagai Toys shopkeeper in The Mysterious Boy. His wife was hospitalized due to a serious sickness, but he's earnings were too modest to afford her treatments, so he was forced to borrow money from Kuromaru Finance. Tsutomu Oshiro, a 38 years old employee, whenever he came by to check on the investment, callously bullied Nagai, which the old man endured for his wife's sake. But then Oshiro decided to demand repayment from the wife, heedless of her condition. When she heard that her husband had plunged himself into debt, she suffered a breakdown which contributed to her death soon afterwards. Then, Nagai murders Oshiro for revenge.
Upon that revelation, Nagai remembers Conan - or rather, Shinichi - from an incident ten years ago, when one of a group of children visiting his toy shop had dropped a toy engine to the floor, breaking it. Shinichi found out which child had done it, but Nagai kindly refused to punish the offender for this accident. The startlement from this realization convinces Nagai to turn himself over to the police, and Inspector Megure orders a thorough investigation of Kuromaru's dubious business practices. When Megure asks Nagai why he has decided to surrender himself, Nagai replies that a "mysterious boy who has remained unchanged for ten years" has influenced him into doing so, as a sort of messenger from his late wife.
Although several characters have caught on to the fact that Conan is much smarter than most children, only a few characters have questioned exactly why he is so smart. Although the FBI are aware of Conan's intelligence and even talk to him like he is an adult (Shuichi Akai), they do not seem to be too concerned about how he got so smart, especially since they have not encountered Conan's true self, Shinichi Kudo. Some of the police like Miwako Sato and Ninzaburo Shiratori take Conan's deductions seriously, but like the FBI, they seem to believe he is just an exceptionally bright child.
 Confirmed suspicious
 Kogoro Mouri
Kogoro was the first character to become suspicious of Conan's identity, albeit briefly. In Volume 2, he felt like he had seen Conan from somewhere before, likely the time when Ran was in elementary school. Later, he noticed that Conan was once again pointing out things he overlooked, such as that all of the photos proving the suspects alibi had clocks in them. However, he instantly loses his suspicions when Conan spills another envelope of photos for the case, deciding that "a brat is a brat" after all.
In the TV Station Murder Case, Kogoro became suspicious about Conan for the second time. He was invited to attend a television live show as a guest star. However, a murder occurred at the studio. After finding out all the evidences, Conan lured Kogoro to a separate room, lying that Yoko Okino was in there. Just as usual, he decided to tranquilize Kogoro and used the man to solve the case. Unfortunately, when Kogoro woke up, he began to question Conan about Yoko's whereabouts. He was also suspicious about the fact that whenever Conan tried to pull him outside, he always fell asleep right after. Kogoro angrily grabbed the boy's suit jacket and wanted to "clear things up". Much to Conan's luck, Yoko Okino appeared for real and Kogoro completely lost his suspicions.
 Ran Mouri
Ran has on more than one occasion noticed the striking similarities between Shinichi and Conan, being his childhood friend and one of the people that know Shinichi the best. She first becomes suspicious during the Episode 7: Once-A-Month Present Threat Case when Conan deduces that the client is a surgeon in a manner similar to Shinichi's deductions, but her suspicions are diluted due to Conan playing with the toys. Later, her suspicions are raised due to Conan acting suspiciously mature for a child and then tricked him into saying indirectly that he's Shinichi. At the end of the episode her suspisions are cleared due to Conan being in the agency while Shinichi( Agasa using a voice changer to mimic)calls the agency. In Episode 96, she sees Conan without his glasses and notices he looks exactly the same as Shinichi when he was a child. She even tries to confront him about it, but Yukiko then arrives and claims that Conan is her distant nephew. Later on, in The Desperate Revival, it is revealed that Ran believes Conan is Shinichi and is waiting for him to tell her. She is only dissuaded from this when Shinichi appears at the same time that Conan does. It turns out that Haibara has given Conan a temporary antidote that will return him to Kudo Shinichi and disguised herself as Conan. After a text message she sends to Shinichi is received on Conan's cell phone her suspicions are aroused again, but Conan uses Agasa's cell phone to call her as Shinichi and messages her his "new" cell phone number. Since then, Ran has apparently been too happy with having Shinichi's "secret number" to become suspicious of Conan. An upcoming suspicion arc has been foreshadowed with Heiji Hattori's omamori and her wondering how Shinichi's fingerprints got on it when only Conan has touched it, coupled with Conan's recent lack of subtlety. And in the Kazuha's Charm Case, Ran told Conan if he has the resolution of the case yet, hinting that she continue suspecting about Shinichi being Conan. Upin witnessing how Conan helps solving cases, it is likely possible that she subconsciously knows that Conan is Shinichi, and due to suspecting him several times, she might be aware that he is using some tricks to create alibis to satisfy her concerns.
 Wataru Takagi
When it seemed they would both die while disarming a bomb, Detective Takagi agreed to follow Conan's instructions in exchange for telling him who he really is. Conan agreed but said he would tell him in the afterlife. Takagi had also thought to himself that Conan was not just any normal kid prior to this, but he has not made this observation since nor has he asked Conan to explain his answer. It is worth noting however that Takagi is aware of Conan's Stun-Gun Wristwatch and will do nearly anything Conan asks him to do, including dressing up as a mailman in order to fool some kidnappers. Also, in a recent case Takagi refers to Kudo as "Shinichi-kun", something that is strange considering that the last contact Shinichi and Takagi had (Shiragami case) he still called him "Kudo-kun", and also in the Shiragami Case he had the same attitude with Shinichi than with Conan in other cases, possibly because he continues suspecting about his identity. However, in the Q&A of the Super Digest Book 80+, Gosho Aoyama stated that Takagi doesn't suspect Conan "even the tiniest bit".
 Keith Dan Stinger
He became amazed by Conan's intelligence by discovering the fake sommelier that tried to poison Princess Mira and how he managed to alert the cockpit of his presence when he jumped onto the plane upon take off. Upon witnessing his actions, Keith reveals his suspicions that although Conan may look like a child, he has the mind of an adult and entrusts him along with Jigen to find evidence that proves Duke Gerard murdered Queen Sakura and Prince Gill.
 Non confirmed suspicious
 Rei Furuya/Tooru Amuro/Bourbon
Rei suspects Conan is creating the Sleeping Kogoro, but it is unclear if he has any suspicions about Conan's identity or relationship to Shinichi. Also, in the final chapter of the Scarlet Showdown, Conan said to him "liar" and then Furuya responded him "look who's talking", possibly because he also noted Conan is not just a very smart boy.
 Jodie Starling
 Shukichi Haneda
Shukichi noticed that Conan is a skilled detective during their first meeting. During a case, he even writes to his sister Masumi that there is no problem if Conan is making the deduction. By the end of the case, he sent her an e-mail asking if she has already met the wizard. Shinichi met Shukichi 10 years ago in the beach, so there is a possibility that Shukichi knows that Conan is Shinichi due to his excellent memory.
 People who questioned Conan's identity
 Kurumi Shodo
Shodo is blind, and based on Conan's speech manner, she concluded that he was in high school age and just had a high voice. She said to Conan that it was as if Sherlock Holmes was imitating a child.
 See also
- List of characters who know Kaitou Kid's identity
- List of characters who know Ai Haibara's identity
- List of characters who know Subaru Okiya's identity
- Shinichi Kudo
- Conan Edogawa
- ^ Aoyama, Gosho (2004-09-07). "File 2" (in English). Case Closed. 1. San Francisco: Viz Media. p. 54. ISBN 1-59116-327-7.
- ^ Aoyama, Gosho (2004-11-03). "File 7" (in English). Case Closed. 2. San Francisco: Viz Media. ISBN 1-59116-587-3.
- ^ Aoyama, Gosho (2005-07-01). "File 1" (in English). Case Closed. 6. San Francisco: Viz Media. ISBN 1-59116-838-4.
- ^ Aoyama, Gosho (2006-09-19). "File 1" (in English). Case Closed. 13. San Francisco: Viz Media. ISBN 1-4215-0443-X.
- ^ Aoyama, Gosho (2007-07-17). "File 8" (in English). Case Closed. 18. San Francisco: Viz Media. ISBN 1-4215-0883-4.
- ^ Detective Conan, File 621.
- ^ Chapter 813
- ^ Paper Airplane Case
- ^ Just Like a 17 Years Old Crime Scene
- ^ File 10, Page 16
- ^ Manga Chapter 11: A Perfect Alibi
- ^ Episode 96.
- ^ Episode 7: Once-A-Month Present Threat Case
- ^ Episode 96: Caught Up With the Great Detective! Two Murder Cases!
- ^ Episodes 188-193: The Desperate Revival
- ^ Manga Chapter 479: The Suspicious Message
- ^ Episode 400: Ran's Suspicions Manga Chapter 483: Unlocking It!
- ^ Manga Chapter 484: From Him to Her
- ^ Manga Chapter 372: The Most in This World...
- ^ Sometime very soon after Scarlet Showdown