Q. Has Stevie Nicks ever done voiceover work for a cartoon or an animated film?

Yes. Stevie voiced the part of “The Owl” in the animated feature The Real Story of…Frère Jacques. Produced by MoonScoop Group (formerly Cinar), this 1994 HBO special provides a “behind-the-scenes” origin story for the classic nursery rhyme. While the animation is fictional, the “Frère Jacques” song itself dates back to 18th-century France and traditionally tells the story of a monk who oversleeps and fails to ring the morning prayer bells.

Reference

Behind The Voice Actors. (n.d.). The real story of Frere Jacques. https://www.behindthevoiceactors.com/tv-shows/The-Real-Story-of-Frere-Jacques/