- Absentee Actor: Bob Uecker was not seen in the last three episodes of Season 5 (except for clips during the season finale), as he was recovering from a heart attack suffered on set.
- Likewise, Rob Stone was not seen in the first half of the series finale as he was co-directing the episode, and 20th Century Fox would not pay him for both directing and acting at the same time.
- Adaptation Displacement | Older Than They Think: If you think not many people remember this show, try finding someone who knows there were a novel and three movies featuring Clifton Webb as a "Mr. Belvedere" character decades before.
- Critical Research Failure: When Mr. Belvedere's novel fails to sell, George tries to comfort him by pointing out that Dr. Seuss' first book was a flop. Belvedere says Seuss's first book was The Cat in the Hat, while George thought it was Horton Hears a Who!. The fact is they're both wrong, as Dr. Seuss's first book was actually And To Think That I Saw It On Mulberry Street.
- Ear Worm: The show's Thematic Theme Tune, a Dixieland-style number performed by Leon Redbone. Don't click on this if you don't want it stuck in your head the rest of the day.
- "Funny Aneurysm" Moment: The running gag about Mr. Belvedere's predilection for junk food becomes a lot less funny in the wake of Christopher Hewett's death in 2001 from diabetes complications.
- Hilarious in Hindsight: Kevin using a video camera for a school project in season 2's "The Lion Sleeps Tonight" is this given that Rob Stone would end up becoming a documentarian after Mr. Belvedere ended its run.
- Making Use of the Twin: Because of California's Child Labor laws, Baby Nelson in season 6's "The Baby" was played by twin brothers Dylan and Samuel Gosland.
- Suspiciously Similar Song: The tune playing during the montage of Kevin performing his nurse duties in one episode sounds a lot like the St. Elsewhere theme.
- Tear Jerker: The final scene with Mr. Belvedere and the Owens family in season 6x22, episode #117, part 2 of the series finale, "Mr. Belvedere's Wedding". After he takes one last look at his bedroom, he then says his goodbyes to each member of the family from oldest to youngest. Of course, he saves the best for last with Wesley, whom, despite the often humiliating moments, loved him very much. It's both funny and sad at the same time.
Wesley: "I know I'm losing my best friend."Mr. Belvedere: "Wesley, I've known heads of state, and many celebrities. But none have given me finer memories than you. I shall savor our moments together. Even the embarrassing and painful ones. Which account for most of them. Though you are an Owens, I shall always think of you as a son."
Wesley: "He's gone."
- The two of them then hug each other. His new wife, Louise, then reminds him it's time to go with her to Africa. After bidding one final farewell, he leaves, and the scenes ends with the family peeping out the front door for one final look, as Wesley says his final line on the show: