DeBlois began his career as an assistant animator and layout artist for Hinton Animation Studios/
Lacewood Productions in Ottawa, Ontario, while simultaneously attending
Sheridan College's three year Classical Animation program in Oakville, Ontario. From 1988 to 1990, DeBlois contributed to such productions as
The Raccoons (TV series), ''The Teddy Bears' Picnic
(TV special), and The Nutcracker Prince'' (feature animated film). Upon graduation from
Sheridan College in 1990, DeBlois was hired by
Sullivan Bluth Studios in
Dublin,
Ireland. There, he worked as a layout artist, character designer, and storyboard assistant to
Don Bluth on such feature animated films as
A Troll in Central Park and
Thumbelina. In 1994, DeBlois left Dublin for
Los Angeles to begin work for
Walt Disney Feature Animation as a storyboard artist, where he worked alongside his frequent collaborator,
Chris Sanders, as Head of Story on
Mulan. Shortly thereafter, they re-teamed to create
Lilo & Stitch. DeBlois left production on
Atlantis: The Lost Empire in order to work on
Lilo & Stitch. Following its release in 2002, DeBlois sold several original live action feature film projects to write, direct, and produce, including an Irish ghost story titled
The Banshee and Finn Magee, a psychological thriller titled
The Lighthouse (not to be confused with the
2016 and
2019 films titled
The Lighthouse) and a family adventure series titled
Sightings, which were optioned at
Walt Disney Pictures,
Touchstone Pictures, and
Universal Studios respectively. DeBlois' feature-length music documentary film
Heima chronicles the homecoming concert of Iceland's
Sigur Rós. In October 2008, DeBlois returned to feature animation to co-write and co-direct
DreamWorks Animation's then-troubled
How to Train Your Dragon, once again re-teaming with Sanders. The duo re-envisioned the film's story and shepherded the production to its March 2010 release. The resulting film became the studio's top-grossing film in North America outside of the
Shrek franchise. During that same time, DeBlois also directed another feature-length music film for
Sigur Rós front-man
Jónsi, entitled
Go Quiet, as well as a feature-length concert film entitled
Jónsi: Live at The Wiltern. DeBlois wrote and directed the
fantasy/
action film How to Train Your Dragon 2, a sequel to the original, which was released on June 13, 2014, followed by
How to Train Your Dragon: The Hidden World on February 22, 2019. On September 23, 2019, DeBlois was attached to write and direct a film adaptation of the
Micronauts. In February 2023, a
live-action adaptation of
How to Train Your Dragon was announced, with DeBlois set to write and direct, making the film his live action debut. ==Personal life==