Dean DeBlois was born in Aylmer, Quebec. He was born poor, and thus he worked in small strip mall where he read the magazines for free. He started his career as an animator in Lacewood Productions in Ottawa. He has contributed to the production for about three years working for a TV series named The Racoons. He had completed his degree in Sheridan College. Upon completion, he was hired directly by Sullivan Bluth Studios which is situated in Ireland, Dublin. There he worked for the featured and famous film named Thumbelina as a layout artist, designer and also an assistant to Don Bluth.By the year 1994 he joined to work with
Walt Disney feature film as a story board artist. The feature film which was released in the year 2002.He has also contributed for a feature documentary music film named “Heima”.By the year 2008 he started his new career as co-writer and co-director for DreamWorks Animation. By the same time he also worked for his another feature documentary music film named Jonsi: Live at The Wiltern.And in the year 2014, he successfully released the fantasy film named How to Train Your Dragon 2 which was wrote and directed by him.
His first film work started in the year 1989 as an assistant animator. By the year 2002, he stared his new career as director for the film Lilo & Stitch.
Apart from films, he has also contributed to several series as a story board writer, screenplay adaption, camera operator, co-writer, layout artist and executive producer. He was openly called as a gay.