Tom and Jerry Meet Sherlock Holmes is a 2010 animated mystery comedy direct-to-video film starring Tom and Jerry produced by Warner Bros. Animation. It is the first Tom and Jerry direct-to-video film to be produced without any of its original creators, William Hanna and Joseph Barbera. It is also considered the first T&J and Tex Avery crossover (due to the presence of nearly the entire Tex Avery character cast). In the city of London, a crook is stealing jewels around the Scotland Yard, and Red, a beautiful singer, is being framed for this crime. Tom and Jerry, as assistants, must help Sherlock Holmes look for clues and track down the real thief to solve this case.
Since its release, it has also aired on Cartoon Network as part of their regular rotation of Tom and Jerry cartoons. The film is also known as Tom e Jerry e Sherlock Holmes (Portugal) and Tom e Jerry: Uma Aventura com Sherlock Holmes (Brazil). This is the first Tom and Jerry direct-to-video (to star or feature Tom and Jerry) film since 2007's Tom and Jerry: A Nutcracker Tale, and it also marks the first animated appearances of Tom and Jerry since Tom and Jerry Tales. Tuffy normally has the same French accent he had in the Two Mouseketeer shorts. This time, voiced by Kath Soucie, he has a Scottish Irish accent.
In Victorian London, an unseen criminal begins masterminding his "perfect plot on paper" which starts with a robbery taking place and three cats stealing a pink diamond. Three constables spot them and give chase, but the cats escape to the rooftops and glide off into the night, giving the stolen diamond to a mysterious horseman. The next day Dr. Watson rushes to 221B in Baker Street and informs his colleague Sherlock Holmes of the robbery. Holmes calls Jerry Mouse to bring him a copy of the Times. Jerry heads out to buy it, bumping into Tom Cat on the way, who has something for Holmes. Jerry sends a pile of bricks on Tom and Tom gives chase. Jerry returns to Holmes' flat and hands him the paper or what was left of it after the chase. Reading a letter Tom had given to them, for the night, Holmes and Watson decide to go to the Bruce Nigel Theatre and see a lady named Red. Holmes is told that she is being blackmailed and Holmes suggests the perpetrator might be - Professor Moriarty. Holmes deduces that the Star of Punjab, a diamond that is light sensitive to the light of a solar eclipse which was to happen the following day, is to be stolen by the mastermind of the blackmail.
At the Punjab Embassy, Spike and Tyke are assigned to guard the Star of Punjab. Spike begins to teach Tyke how to be a good dog guard, but the three cats from the previous night steal the diamond while an unfocused Spike is not looking. The three cats then leave a small button and retreat. They climb out through a hole in Red's home that leads to the tunnel and escape before Holmes, Tom and Jerry arrive. Upon arriving, Jerry tricks Tom into stepping into a broken board and the trio check the tunnel. Finding sawdust, they retreat once hearing Tyke sounding the alarm. Holmes and Watson leave to find the shop from where the button came from, while Tom and Jerry are left to take Red to Holmes' flat.
The police believe Red is behind the crimes and offer a reward for the one who finds her. Butch and Droopy move in to take the case and race to see who gets it. Butch then bumps into Tom, Jerry and Red. They begin a tiring chase and Tom drops a lantern on Butch's head. They run to St. Paul's Cathedral and are let in by Jerry's brother Tuffy. Tuffy and Red escape but Tom and Jerry hide in the organ. Droopy and Butch then play a song on it and send Tom and Jerry flying out of the cathedral.
Tom catches his back in a pitchfork and Jerry informs Tuffy and Red that the cats are inside the pub, The Twisted Lip. Red distracts the cats while guiding Tom, Jerry and Tuffy to the cats, the former getting punched in the face on the way by a customer (for bringing his drink to a different customer). Although the cats escape in time and kidnap Jerry, Tom follows them and rescues Jerry, except for the diamond. They are sent flying again, and Jerry lands to safety, but Tom lands on another pitchfork. The trio follow the cats to a graveyard and find the diamond. However, the mysterious horseman from previously gets there before them but Jerry secretly steals a key. Red decides to go to her friend's place, who is a professor.
Red is brought in by the professor but accidentally bashes Tom in the face with the door, leaving him, Jerry and Tuffy locked outside. They then see Butch and Droopy coming their way and hide in a stable. Tom catches his bottom on a pitchfork again and Jerry is forced to cover his screams. They find the horse belonging to the mysterious horseman and discover that the thief is in the house, also that Red may be in danger! They use the key they got to sneak inside and they find a machine containing the stolen diamonds. Tuffy catches the Star of Punjab but slips on the chimney. Tom and Jerry stumble after him but find that Red is tied up. The professor captures the trio and reveals himself as Moriarty and reveals his plans to steal the Crown Jewels. By using the eclipse's light, Moriarty will utilise the diamonds as a heat-ray that would fire and ricochet off several mirrors, planted on many of London's landmarks, and slice a hole into the Tower of London.
Moriarty then makes his way to the Tower of London with a captive Red. Spike and Tyke are left to guard the Crown Jewels after the incident at the Embassy, but the sliced wall from Moriarty's heat-ray crushes Spike and Moriarty's cats steal the Jewels. However, Tom knocks out one cat and tricks him into firing the ray on the cage setting them free. They use the cat's winged backpack to fly to the Tower but Moriarty escapes with the Jewels. Tom then crashes into the carriage and they free Red. Jerry frees the horse and spots Holmes and Watson making their way to Moriarty (who earlier had been deduced by Holmes to steal the Jewels). Butch fails to catch the cats and Droopy sends them into the Tower, where they are beaten up by Spike.
Moriarty activates his horseless carriage and he and Holmes fight atop the carriage. Tom accidentally breaks the brake and the carriage steers off an unfinished Tower Bridge. Red, Tom, Jerry and Tuffy make it back to the bridge but believe Holmes to be dead. However, Watson arrives and finds Holmes clinging to an edge with the Jewels. Moriarty and the three cats are arrested but Droopy gets the reward instead of Butch, having chained him to a fence when he wasn't looking.
At St Paul's, Red marries a wolf and they start howling and run off. While Holmes and Watson watch them run off, Jerry then secretly sets Tom's tail on fire and Tom gives chase to Jerry. It is then revealed that Droopy had done the wedding, and Droopy smiles at the screen.