When Oliver wakes up after sleeping on the truck tire, he sees people crossing past the alley where he's slept. One of those people is Roger from 101 Dalmatians (1961) (look for the guy with the brown hair, blue shirt, and blue pants).
Like many pre-1989 Disney Films, the video release of Oliver & Company (1988) was delayed for years. Despite this film being released in 1988 and being a commercial success, it was not released on video until 1996.
Dom DeLuise had already had roles in several other animated films by this point, namely those by Don Bluth, but this was the only time he got the chance to voice a character in a Disney film. He loved the role so much, he kept ad-libbing lines that ended up being included in the film. He even chose to be in Oliver & Company (1988) over Bluth's The Land Before Time (1988) which released on the same day.
Early in the film's development it was decided that it would be a sequel to The Rescuers (1977). The producers then decided that the story wasn't convincing and started from scratch. The only things left are the New York setting and a few similarities between Jenny and Penny.
One of few animated films to feature a front-and-center shot of New York City's Twin Towers. After the tragedy of 9/11, when shots of the iconic towers were being removed from many films to avoid upsetting people, Disney opted not to attempt to edit out the towers, mostly because it would ruin the film's original main title card and because it would be too time-consuming and costly to do. By 2001, Oliver & Company had already been widely distributed on VHS, so there was no point in editing it. Many New Yorkers later commended Disney not altering the film because they felt it was a good portrayal of the way New York used to be before 9/11, and they wanted it left as it was with the towers visible.
Many of the inanimate objects in the film were created and animated on the computer: cars, cabs, buses, Sykes' limousine, Fagin's trike (part-scooter and part-shopping cart), a cement-mixer, a sewer pipe, a spiral staircase, a piano, subway tunnels and trains, cityscapes, and even the Brooklyn Bridge.
This film along with Aladdin (1992) are the only Disney animated feature films where Frank Welker doesn't just make animal noises. Welker in this film even voices Louie the Hotdog Vendor, and would later fill in for voicing Dodger in one of the House of Mouse (2001) episodes.
Oliver & Company was the favorite film of Bailey Kane, a traumatized corporate lawyer in the book Bittersweet Symphony (ISBN 978-1975874513), which she mentions as being a film she went to see as a child when it hit theaters.