Actress Lynda Carter was initially given gold bracelets to wear as an homage to her 1970s Wonder Woman (1975) role. Warner Bros., who owns copyright to the Wonder Woman character, didn't want the bracelets shown in a Disney movie so they were removed from Carter's wardrobe for the film. She did however get to say the line "I'm not Wonder Woman, you know" in one of the last scenes of the movie.
The phone number for Stronghold Realty is 800-656-1482, which is a number at ABC, which is owned by Disney. The voicemail message was: "Thank you for calling ABC, the number you have reached is a fictional non-working number used for motion picture, and television production." The number can be seen near the end of the movie when Mr. and Mrs. Timmerman are admiring their new house, which is about to be crushed by Sky High, the camera pans by the Stronghold Realty sign. However, the number no longer gives that message. It now says: "In order to better direct your call, please state the company and the ten digit phone number you are attempting to reach."
The comment Mr. Boy makes about sidekicks not wearing costumes with colors that clash with their hero's is a jab at comics' most famous hero/sidekick team, Batman and Robin. Where Batman wears dark colors (blue and gray) Robin wears bright colors (Red, green and yellow)
The role of Speed was intended to be for an exceptionally athletic boy, but when Will Harris auditioned, the casting director found him so like-able that the role was changed to accommodate his larger stature.
According to actors who auditioned for various roles in the production, the main children's parts are to be contracted for not only a sequel but also a possible television series on the cable Disney Channel.
Each of the main characters has his or her own color scheme, wearing the same colors throughout the movie. Will's colors are red, white, and blue. Layla's is green. Gwen's is pink. Warren's is red and black. Zack's is yellow. Magenta's is purple. Ethan's is orange.