The story begins in New York City, Oliver, an orange kitten, is lost in the streets. He is hungry and tries to steal some hot dogs from a hot dog vendor, but without success. When Garfield, Charlie Barkin, and Itchy Itchiford introduce Winnie the Pooh, Piglet, Tigger, Rabbit, Eeyore, Kanga, Roo, Lumpy, Darby, Buster, Ash Ketchum, Pikachu, Misty, Brock, Togepi, The Vultures (Buzzie, Flaps, Dizzy, and Ziggy), Jiminy Cricket, Zazu, Scooby-Doo, Shaggy Rogers, Fred Jones, Daphne Blake, Velma Dinkley, Tennessee Tuxedo, Chumley, Ttark, Poky Little Puppy, Shy Little Kitten, Tip, Dash, and Odie to Oliver, a street-smart, wise-talking mongrel - judging from appearances, some sort of Terrier crossbreed - named Dodger offers his help. Together they are successful, but Dodger runs off, attempting to leave the orphaned feline behind. He is mildly surprised when Oliver overtakes him, attempting to take his half of the meal, but continues to evade the pursuing kitten with relative ease, showing off his street skills in the process while singing the song "Why Should I Worry?”
Dodger eventually arrives at the barge of his owner, a pickpocket by the name of Fagin and along with Fagin's meal, to give to his friends: Tito the fiery Chihuahua, Einstein the ironically-named Great Dane, Rita the Saluki and the ever-serious Francis (Frankie), the Bulldog. No sooner do Oliver, Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, and their friends sneak into their home, located below the city's docks, than the dogs get into a fit of fighting and confusion over their visitors. Breaking it up is Fagin himself although he also has to deal with Einstein licking his face with a huge slobbery tongue and the rest of the dogs jumping on him because he came in with a box of doggie treats. Fagin came in to see what goods the dogs have stolen during the day for them to live on. He's terrified to discover that the dogs have returned with some worthless trinkets. He informs them that he is running out of time to repay the money he borrowed from Sykes, a ruthless shipyard agent and loan shark. When Sykes arrives, he sends in his two savage Doberman Pinschers, Roscoe and Desoto, along with Carface, Killer, and Team Rocket (Jessie, James, and Meowth), to fetch Fagin. Going out on a long quay, he sees Sykes waiting in his car, a Lincoln Continental Mark IV with a license plate reading "DOBRMAN". Sykes outlines his conditions: the money must be paid in three days, or else. Fagin knows that he can't find the money, and that he is in a lot of trouble. During this scene, Roscoe flirts with Rita as Desoto finds and attacks Oliver, who scratches his nose. Dodger and his gang (along with Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, and the others) defend Oliver and the two Dobermans leave when Fagin arrives. Admiring Oliver's courage with DeSoto, Fagin welcomes the kitten into the gang.
Next day, Fagin sets out into the city with his canine menagerie; Oliver included, and tries to sell his wares at a pawn shop, with no success. The animals (along with Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, and their friends), meanwhile, come face-to-face with a limousine driven by a butler named Winston. Winston is employed by the Foxworth family and is taking care of their daughter Jennifer while the couple is out of the country, taking a business trip in Europe. The dogs (along with Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttrak, Garfield, and the others) stage an elaborate ruse in order to get Winston out of the car. While Lumpy watches, Tito, Piglet, Roo, Pikachu, Jiminy, Zazu, Itchy, Garfield, Odie, and Oliver slip in and attempt to steal its radio to give to Fagin so that he'll have something to pawn to pay back Sykes. In doing so, Tito gets comedically shocked by the electrical system, Piglet, Roo, Pikachu, Jiminy, Zazu, and Itchy run out of the car with Lumpy, and Jennifer finds Oliver all tangled up in the wires near it. Oliver finds a good home and a caring owner in Jenny, to the chagrin of Winston and the Foxworth's pampered, pedigreed poodle, Georgette.
Back on the street, Fagin's dogs (along with Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, and their friends) are discussing on a plan to retrieve the cat back to their home barge. The plan is activated the following day, not knowing that Oliver is now happy where he is. During the operation, Tito falls in love with Georgette, much to her disgust.
Back at the barge, Oliver feels that he does not want to go back to his dog friends (along with Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, and the others) because Jenny is his owner now. Little does he know that he himself is Fagin's best hope for paying Sykes, for when the poor man comes back from business, and sees the gold tag on the cat's collar, he has an idea: with only pencils and paper, he writes to the "Very Rich Cat Owner Person" at Oliver's address, along with a map to guide the addressee to his home.
Along with Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, and their friends, Fagin now has to convince Sykes that his plan is air-tight enough to pay him his money. Entering Sykes' building, the loan shark is not pleased to see Fagin does not have the cash, and orders his Dobermans to attack. Dodger defends Fagin, and Fagin pleads once more with Sykes. When Sykes sees Oliver's gold tag, he believes that Fagin is finally "starting to think big", and calls off the dogs, giving Fagin twelve hours and warning Fagin, "This is your last chance."
When Jenny returns home from school, she finds the letter. Reading it, she realizes that she has to pay a large ransom in order to get her cat back. That night, she sets off for the city docks along with Georgette to do so, along with the enclosed map. Once they arrive there, Fagin's dogs, Pooh, Ash, The Vultures, Jiminy, Zazu, Charlie, Tennessee, Ttark, Garfield, Georgette, and the others concoct another series of plans to save Jenny. But while they try to do so, Sykes and his Dobermans get in their way before Fagin crashes in on his scooter/shopping cart/road block-combo to pick them all up. A chase down the city streets and into the subway ensues, Fagin and the gang racing away with Sykes raging behind them. Jenny is thrown onto the hood of Sykes's car, and Oliver jumps and bites his hand, in order to save Jenny. Unfortunately, he's sent to the back seat, where Roscoe and DeSoto are waiting for him. Dodger saves Oliver by forcing the two Dobermans out of the car, and causes them to fall onto the electric tracks, killing them both. A train approaches all of them, and Fagin and the gang swerve over on the left side of the Manhattan Bridge to avoid it. But for Sykes, however, it is too late: he is killed when the train crashes into him and his black car, sending what's left of both falling into the river. Tigger blasts off Team Rocket and Charlie tells Carface and Killer to go back to where they belong.
Descending from the railings, everyone wonders what has happened to Oliver and Dodger; but as Dodger brings him out before the rest it seems that Oliver is dead. Then while Jenny's crying the kitten weakly mews, a joyful sign that he is alive. Rabbit says "Oh, thank goodness you're safe." and Tigger says "We're so glad to see you."
Next morning, Fagin and the entire group celebrate Jenny's birthday party at her home. That same day, Winston receives a phone call from Jenny's parents in Rome that they will be back tomorrow. Dodger promise Oliver that they will return from time to time to visit him. Soon, Fagin and his companions bid farewell to the Foxworths and Oliver as they head home through the crowded streets of New York City. Pooh and their friends (including Jiminy Cricket) go back to the Hundred Acre Wood, Ash and his friends go back to where they belong, The Vultures go back to India, Zazu goes back to Pride Rock, Charlie and Itchy go back to San Francisco, Tennessee Tuxedo and Chumley go back to their zoo, Ttark goes back into the wild, Poky and Shy go back to their home, Tip and Dash return to where they belong, and Garfield and Odie go back to the house of their owner Jon.
- Ash Ketchum, Pikachu, Misty, Brock, Togepi, The Vultures (Buzzie, Flaps, Dizzy, and Ziggy), Jiminy Cricket, Zazu, Charlie Barkin, Itchy Itchiford, Scooby-Doo, Shaggy Rogers, Fred Jones, Daphne Blake, Velma Dinkley, Tennessee Tuxedo, Chumley, Ttark, Garfield, Odie, Poky Little Puppy, Shy Little kitten, Tip, Dash, Carface, Killer, and Team Rocket (Jessie, James, and Meowth) guest star in this film.
- Oliver is revealed to be a cousin of Garfield and Einstein is revealed to be a cousin of Scooby-Doo in this film.
- This film marks the first debut of Darby and Buster from My Friends Tigger & Pooh.
- Simba, Nala, Timon, and Pumbaa were originally planned to guest star in this film, but Yru17 found out that LionKingRulezAgain1 is already planning to make Simba, Timon, and Pumbaa's Adventures of Oliver & Company, so he decided to cut them out of this film to avoid confusing the audience a bit and have them replaced with Charlie and Itchy.
- Danny and Sawyer were originally planned to guest star in this film making Oliver their son, but the idea was put into Legoland1085's project Dave Felis Meets Oliver and Company, so yru17 ended up replacing them with The Vultures, Jiminy Cricket, and Zazu. However, Garfield and Odie will guest star in this film making Oliver a younger cousin of Garfield.
- Originally there was a request for a Pokémon crossover film with Oliver & Company, but the idea was quickly dropped because the first episode of Pooh's Adventures of 101 Dalmatians: The Series marked the first time Ash and the gang met Oliver when he originally guest starred in that episode way before YakkoWarnerMovies101 decided to replace him with Simba, Timon, and Pumbaa. However, after ToonJoey34 explained that Ash and the gang actually met Oliver before that episode, the characters ended up guest starring in this film instead.
- This is the only Winnie the Pooh crossover with a 1980's Disney animated film with Ash and his friends as guest stars, since the characters will have their own adventure in Ash's Adventures of The Little Mermaid and will guest star in Littlefoot's Adventures of The Black Cauldron, Littlefoot and The Adventures of the Great Mouse Detective, and Littlefoot Meets The Fox and The Hound.
- This is an NTSC film, with NTSC bits from the Winnie the Pooh films, the Pokémon films, The Jungle Book 1 and 2, Pinocchio, Mickey's Christmas Carol, The Lion King 1 and 2, the All Dogs Go the Heaven films, the Scooby-Doo films, and The Little Mermaid II: Return to Sea.
- The TV show The New Adventures of Winnie the Pooh was on ABC Saturday mornings at the time when Oliver & Company was released in theaters in 1988.
- Oliver & Company was re-released in theaters on March 29, 1996, the same day All Dogs Go to Heaven 2 was released in theaters. This happened during the same year The Many Adventures of Winnie the Pooh was re-released on home video celebrating the 30th anniversary of Winnie the Pooh's theatrical debut (back when the very first Pooh short Winnie the Pooh and the Honey Tree was released in theaters in 1966).
- Both Itchy and Fagin were voiced by the late Dom DeLuise, which the film will be dedicated to due to his death back in 2009.
- According to the Internet Movie Database, Burt Reynolds, who voiced Charlie in the original All Dogs Go to Heaven, was originally going to voice Dodger back when Oliver & Company was still production, but Billy Joel took over the role for the voice of Dodger.