The film stars Peyton Elizabeth Lee, Niles Fitch, Isabella Blake-Thomas, Olivia Deeble, Noah Lomax, Faly Rakotohavana, Ashley Liao, Sam Page, Greg Bryk, Élodie Yung, and Skylar Astin, and was produced in association with Disney Channel.

In the kingdom of Illyria, second-born royal Princess Samantha "Sam" argues against the monarchy with her friend, Mike, by performing rock music on the streets.

Their teacher is Professor James Morrow who reveals that they are not there to take summer school, but instead are to be trained to join the Secret Society of Second-Born Royals, a group of superpowered individuals dedicated to protecting the world and serving the various monarchies.

In May 2019, it was reported that Secret Society of Second-Born Royals was in development for Disney+ with executive producers Austin Winsberg and Mike Karz, directed by Anna Mastro,[3] and written by Alex Litvak and Andrew Green.

The site's critics consensus reads: "Secret Society of Second-Born Royals holds up just well enough to suffice as a streaming diversion -- which may be all its target demographic is looking for.

[13] Brian Lowry of CNN complimented the humor of the film and the story, writing, "Disney actually has a promising teen-driven movie indebted to the X-Men franchise.

"[15] Molly Freeman of Screen Rant rated the film 3 out of 5 stars, complimented the humor of the movie and the performances of the cast members, writing, "Secret Society of Second-Born Royals is pure family-friendly fun, combining princesses and superheroes for a delightful, if unoriginal, adventure.

In the end, Secret Society of Second-Born Royals is fun for the whole family, with enough Disney magic to tide over fans of the Mouse House at a time when there's a dearth of new movies from the studio.

"[16] Jennifer Green of Common Sense Media rated the movie 3 out of 5 stars, praised the presence of positive messages and models, saying, "The teens learn about teamwork, friendship, and the value of traditions -- and also about betrayal and people who are willing to kill for their own purposes.

There are some positive messages here that could hit home with younger viewers, including teen characters needing to master their own insecurities and learning to care about other people and spend less time online.

"[17] Sunayana Suresh of The Times of India gave the film a 2.5 out of 5 stars rating, complimented the premise and the performances of the actors, but found the movie lacks a thrilling narrative depiste having the potential to build a franchise.