Justin Chatwin was born in Nanaimo, British Columbia, to Suzanne, an artist, and Brian, an engineer. He was raised Catholic. He did not initially want to be an actor, but a friend invited Chatwin to audition as an extra for the movie Josie and the Pussycats. He enjoyed the experience and ended up playing a fan. After that, his parents encouraged him to give up university and pursue an acting career. Chatwin found an agent, and in 2001 began appearing in Canadian TV shows. He studied commerce at the University of British Columbia and took acting lessons in his spare time.
He moved to Los Angeles in 2005 and until 2009, he lived in a small apartment with his roommate, actor Noel Fisher, who years later co-starred with him in Shameless. He has two sisters, Brieanne and Claire. His passions are film, photography, and adventure. He was an avid snowboarder when he lived in Canada, and is a fan of Chemical Brothers and Arcade Fire.
Justin Chatwin made his film debut in the musical comedy Josie and the Pussycats. After that, he had guest appearances in Canadian TV shows like Smallville, Just Cause, Glory Days, Mysterious Ways and supporting roles in films like Taking Lives and Superbabies: Baby Geniuses 2. He gained recognition in 2004 for his role as Tyler McKay in the American miniseries Traffic. For his performance, Newsweek magazine dubbed Justin as the "Actor to Watch".
Following this success, was chosen to play Tom Cruise's son in the summer blockbuster War of the Worlds, directed by Steven Spielberg. Also in 2005, he was seen in the independent black comedy The Chumscrubber alongside Jamie Bell, Carrie-Anne Moss and Lou Taylor Pucci. In the same year, he played the son of Kevin Nealon's character in the Showtime comedy series Weeds, appearing only in the pilot and series finale. Next year, he had a guest appearance in the highly popular TV show Lost and starred in the play Dark Matters who ran from November 10, 2006 through December 22, 2006 at The Rattlestick Playwrights Theater in New York.
In 2007, The Invisible was released, a remake of the Swedish film Den Osynlige, which marked his first lead role. Next year, he returned to the independent film world, having a supporting role in Middle of Nowhere, a coming of age drama directed by John Stockwell, starring Eva Amurri, Anton Yelchin and Susan Sarandon.
In 2009, Chatwin portrayed Goku in Dragonball Evolution, a big screen adaptation based on the Japanese Dragon Ball manga by Akira Toriyama. Chow Yun-fat, James Marsters and Jamie Chung co-starred in the film. Then, he returned to Canada to shoot Funkytown alongside huge Canadian film stars like Patrick Huard and Paul Doucet. Later in 2009, he was cast as Jimmy Lishman in the Showtime pilot Shameless, opposite William H. Macy and Emmy Rossum. The project was picked up and Chatwin was a series regular for 3 seasons (2011 - 2013). He returned for the season 4 finale and joined season 5 as a special guest star.
Between those years, Chatwin made a short film called Brink, written and directed by one of his friends, Shawn Christensen which premiered in 2011 at the Tribeca Film Festival and also had a guest appearance in season 3 of The Listener opposite Craig Olejnik.
After Shameless, Justin Chatwin pursued his film career with roles in the sci-fi musical Bang Bang Baby, 2015 Toronto International Film Festival winner for Best Canadian Film and the romantic comedy No Stranger Than Love with Alison Brie and Colin Hanks. His upcoming projects includes Urge, a thriller in which he will star alongside Pierce Brosnan and Ashley Greene, an adaptation on Nancy Pickard's novel The Scent of Rain and Lightning, the comedy Unleashed, written and directed by San Francisco filmmaker Finn Taylor, Minhal Baig's romantic drama One Night, In the Lost Lands, a fantasy-adventure film based on three short stories by Game of Thrones American novelist George R.R. Martin, and a cameo in the upcoming action-comedy CHiPs with Dax Shepard, Michael Peña and Vincent D'Onofrio.
Also, in 2016, Justin returned to television with a leading role in CBS murder mystery summer series American Gothic alongside Megan Ketch, Antony Starr and Virginia Madsen, which premiered June 22. He also starred in BBC's Doctor Who 2016 Christmas special "The Return of Doctor Mysterio" playing a superhero named The Ghost.
In 2004, Justin Chatwin shot a pilot for WB that was not picked up called Prodigy, a drama about a teenage girl who hides her music talents from her family, who are busy focusing their attention on her younger brother, a well-known prodigy. He played a supporting role opposite Kate Mara and Cody Arens.
In 2005, Chatwin was supposed to produce and star in an adaptation of Michael Turner's 1999 cult novel The Pornographer's Poem, a coming of age comedy about a teenager who enters into the world of pornography when he witnesses his neighbours engaged in sex on their back porch. Jeremiah S. Chechik has been attached to direct. Next year, the actor was set to star alongside Kristin Kreuk in Private Wars, a drama centered on three male combat veterans and their time in the hospital recovering from the war.
Two years later, Chatwin began to develop two movies: Wrench, a thriller that he co-wrote with a playwright from New York City, and The Last Rustler, a modern western, described as a cross between Raising Arizona and No Country for Old Men. He intended to star and produce alongside Bill House. Also, from 2007 to 2011, Justin was attached to star with Spencer Treat Clark, Matt Long and Jamie King in Riding the Pine, a drama directed by Jeff Woolnough about two brothers who take a road trip after one of them contracts a terminal illness.
Justin was set to reprise his role as Goku in Dragonball Evolution sequel, but the original film was a box office bomb, so 20th Century Fox cancelled the project which had the working title Dragonball 2: Reborn.
At the beginning of 2015, Chatwin has been tapped to lead the TNT pilot Breed, a supernatural drama about a series of brutal murders in the Pacific Northwest and a gifted detective who embarks on the case, employing his expertise on serial killers. Shaun Majumder, Aisha Hinds and Nadia Hilker co-starred with him but the project was not picked up as a TV series.
From 2005 to 2009, Chatwin was in a long relationship with actress Molly Sims. He also dated Addison Timlin.