What is the name of the stop-motion animation studio that produced 'The Nightmare Before Christmas'?

The stop-motion animation studio that produced The Nightmare Before Christmas was Skellington Productions.

Skellington Productions was a joint venture involving Walt Disney Feature Animation, Tim Burton, and director Henry Selick. The company specialized in stop-motion work, making it distinct from Pixar, which is associated primarily with computer-generated animation, and Laika, which produced later stop-motion features.

The film was released in 1993 under Disney’s Touchstone Pictures label. That branding often causes confusion: Disney financed and distributed the project, but Skellington Productions is the production company credited with making it. Henry Selick directed the film, while Burton produced it and supplied the original story concept.

Production began in July 1991 in San Francisco. Animators photographed 109,440 individual frames and built 227 puppets; Jack Skellington alone had roughly 400 replacement heads for different expressions. Skellington later worked on projects including James and the Giant Peach before Disney closed the company in 1998.