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.
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.
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" 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, 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.