Daniel was born in Winnipeg, Manitoba, Canada. His father is a pediatrician. He was raised in New Zealand and went to Southwell School and the Hamilton Boys' High School. He made his acting debut in Street Legal. His next bigger role was in Spider-Man 2, where he played John Jameson, a fiancee of Mary Jane Watson (Kirsten Dunst). Gillies starred in his acting debut in the New Zealand drama Street Legal, where he played Tim O'Connor (2000–2002). He was featured in the movie Spider-Man 2 (as John Jameson) alongside Kirsten Dunst and Tobey Maguire. He guest-starred on NCIS as a British MI-6 agent, and on The Vampire Diaries as one of the Originals, Elijah.He also worked with Ian Somerhalder in the film Sensasion Of Sight.  As of June 2012, he appears in the NBC medical drama, Saving Hope. Gillies plays Joel Goran, the hotshot young surgeon. Gillies' other television credits include HBO's True Blood and A&E's The Glades. Other guest appearances include Masters of Horrors, Jeremiah and Mentors. A veteran of the theater, Gilles participated in over twenty plays professionally; including Julius Caesar, Three Sisters, Long Day's Journey into Night and The Judas Kiss. In 2006, he played a lead in the International Festival film The Sensation of Sight, alongside Academy Award nominee David Strathairn. The following year, Gillies started his own production company – Holy Monster. In 2010, Gilles wrote and directed his first independent film Broken Kingdom. The film was shot in Bogotá, Colombia and Los Angeles. It can be downloaded via its official website for only 5 dollars. he also worked in Gurinder Chadda's Hollywood film called Bride and Prejudice as the role, Johnny Wickham, along with the actress and former Miss World, Aishwarya Rai.
He has been married to actress Rachael Leigh Cook since 2004. He made a movie called "Broken Kingdom" in which he and his wife play the main roles. Rachael and Daniel have one daughter, Charlotte Jamila Easton Gillies, born September 2013. On 22 January 2015, it was announced that they are expecting their second child. Their son, Theodore Vigo Sullivan Gillies, was born on April 4, 2015.
- Daniel Gillies is one of the seven actors in Vampire Diaries who has also been in another vampire show, True Blood, the others include Arielle Kebbel (Lexi), Cherilyn Wilson (Samara in the episode, The Birthday), Courtney Ford (Vanessa Monroe in the episode, Bad Moon Rising), James Harvery Ward (Cody in the episode The Sacrifice), Adina Porter (Nandi in the episode We'll Always Have Bourbon Street) and Janina Gavankar (Qetsiyah/Tessa)
- Daniel Gillies is team Delena, Elejah and Gilijah.
- Between 2012 and 2015, Daniel Gillies played simultaneously on two TV shows at the same time; first with The Vampire Diaries and the Canadian TV show Saving Hope and then on The Originals and Saving Hope up until February 2015 when his character, Dr. Joel Goran was killed off Saving Hope.
- He had made a special appearance in 500 Years of Solitude (100th episode of The Vampire Diaries), along with David Anders, Sara Canning, Matt Davis, Kayla Ewell, Claire Holt, Bianca Lawson and Joseph Morgan.