How to Train Your Dragon: The Hidden World is a 2019 American animated fantasy film loosely based on the book series by Cressida Cowell.

[4] Written and directed by Dean DeBlois, the film stars the voices of Jay Baruchel, America Ferrera, Cate Blanchett, Craig Ferguson, and F. Murray Abraham, with Gerard Butler, Jonah Hill, Christopher Mintz-Plasse, Kristen Wiig, Justin Rupple (replacing T.J. Miller), and Kit Harington in supporting roles.

Like its predecessors, it received positive reviews from critics, with praise for its animation, voice acting, musical score, and emotional weight.

In response, Hiccup desires to find the "Hidden World", a safe haven for dragons once spoken of by his late father, Stoick.

Seeing Toothless' inability to fly solo hindering his growing relationship with the Light Fury, Hiccup rebuilds an automatic tailfin for him.

After introducing his son and daughter to his old friend, Hiccup and Astrid take their children flying on Toothless and Stormfly, accompanied by the Light Fury and their offspring.

In December 2010, DreamWorks Animation CEO Jeffrey Katzenberg announced that there would also be a third film in the series: "How To Train Your Dragon is at least three: maybe more, but we know there are at least three chapters to that story.

[16] Jay Baruchel, Gerard Butler, Craig Ferguson, America Ferrera, Jonah Hill, Christopher Mintz-Plasse and Kristen Wiig returned in the third film,[16] with Justin Rupple replacing T.J. Miller as Tuffnut.

[10] DeBlois revealed that Miller did originally return to voice Tuffnut, but DreamWorks recast him after the actor's sexual assault allegations and arrest for calling in a fake bomb threat.

[25] In September 2012, 20th Century Fox, DreamWorks Animation's then-distributor partner, and the studio itself announced the film was originally going to be released on June 17, 2016.

I think it was a little ambitious to say 2016... As is normally the case, they kind of throw darts out into the future and wherever they land they call that a release date until we start talking about it in practical terms, and then it's like, 'Uh yeah that's not enough time'.

[3] Deadline Hollywood calculated the film's net profit as $130 million, accounting for production budgets, marketing, talent participations, and other costs; box office grosses and home media revenues placed it 12th on their list of 2019's "Most Valuable Blockbusters".

[38] In the United States and Canada, How to Train Your Dragon: The Hidden World held early screenings at 1,000 theaters on February 2, 2019 and grossed $2.5 million, one of the highest advance showing totals ever.

[39] It was released alongside the wide expansion of Fighting with My Family, and was initially projected to gross $40–45 million from 4,259 theaters in its opening weekend.

The website's critical consensus reads, "The rare trilogy capper that really works, How to Train Your Dragon: The Hidden World brings its saga to a visually dazzling and emotionally affecting conclusion.

"[49] Michael Nordine of IndieWire gave the film a B, saying, "Directed once again by Dean DeBlois, The Hidden World strikes a bittersweet chord in reminding its young audience that all good things — including the age of dragons — must come to an end."

"[50] Ben Kenigsberg of The New York Times gave a positive review of the characters and emotional messages of the film, writing "More bittersweet and less triumphal than its predecessors, and directed by a returning Dean DeBlois, The Hidden World concerns the exigencies that Hiccup faces as a leader, both politically and personally.

"[51] Conversely, some critics felt the film had the presence of too many juggled sub-plots and an obligatory ending, with Movie Crypt concluding that "Fans will enjoy seeing their characters grown and progressing as story arcs are closed, but the final resolution rings hollow.

"[52] Kerry Lengel of The Arizona Republic says that "The plot is thin and holey and the characters are mostly just a single gag set on repeat" and calls it "a lazy effort".

Set before the epilogue of The Hidden World, it depicts Hiccup and Astrid teaching their children about the friendship between humans and dragons in order to protect their legacy.

An animated television series, titled Dreamworks Dragons: The Nine Realms, premiered in October 2021, and ran for eight seasons, concluding in December 2023.