Principal William S. Willoughby is a supporting character in the franchise and the principal of Lindbergh Elementary School. He is voiced by Rob Paulsen. He can be described as energetic, enthusiastic, and over the top. He seems to be everything a good elementary school principal should be. He is approachable, kind, strict, and has a gentle nature to him, not to mention the fact that he's fairly clueless when it comes to most aspects of life. Despite this fact, he seems to have a knack for his chosen profession. He seems to genuinely care about his students and has clearly taken the time to get to know each and every one. In Beach Party Mummy, Principle Willoughby found out he has been tricked by the kids ("Wait a minute! We don't have a tanning salon!")
Most of what we know about Principle Willoughby is often revealed in the show’s dialogue, so we have to be paying attention or we miss out on some important tidbits about his past. In Out, Darn Spotlight we learn that Mr. Willoughby and Corky Shimatzu were roommates at Vassar, which is a small private liberal arts college nestled in the Hudson valley about 75 miles north of New York City. Vassar was founded in 1861 as a women’s only college up until 1969 when it went co-ed. No one knows what year Mr. Willoughby graduated, or whether or not he continued to get his Masters, but it would seem he majored in Education possibly with a minor in Performing Arts (both available at Vassar). This could be the vehicle that drives Principle Willoughby to encourage performing arts education at Lindbergh, and for good reason. It’s obvious that music and the arts are a keystone in his life. He frequently makes references to classic Hollywood and even mentions having 'dressed up' as Michelangelo's naked statue "David" for Halloween ("sure was chilly that year!")
Principle Willoughby is ever present at the school’s various extra-curricular events such as student elections and assemblies. In “Jimmy for President” one can’t help but laugh when Principle Willoughby mumbles, “Can we afford funk every day?” to Miss Fowl after Libby’s speech. In all cases, he always seems to be encouraging the students or possibly saving them from themselves. When we examine Principle Willoughby further, we can see an aspiring play-write and composer. Musical Theater appears to Mr. Willoughby’s first love and is eager to share this love of theater with his faculty, students, and the parents of Lindbergh Elementary. He is credited with writing the admittedly bizarre play “Macbeth in Space” and expresses plans to do an encore feature, "Hamlet on Ice". In “Attack of the Twonkies” he composes the new library dedication song, which sounds more like a Broadway show tune than anything else.
Possibly a bit too trusting and naive (take, for example, his belief in Sheen's claim that they were all going to "the tanning salon" in Beach Party Mummy ), Principle Willoughby is nevertheless open, fair and kind to the students of Lindbergh Elementary . He is high-energetic with a subtle and charming wit.