Samuel made his debut on the Australian TV show ''
McLeod's Daughters in 2003. He starred in the Australian horror movie Road Train as Marcus, and also acted in the Australian movie Drowning
with Elephant Princess'' star Miles Szanto, directed by
Craig Boreham. Alongside
Mia Wasikowska, Samuel was in the 2007 Australian film
September, set in 1968 where two young boys who share a passion for boxing are friends. In 2008, Samuel starred in the Australian surfing movie
Newcastle, opposite
Reshad Strik. In 2009, Samuel was cast as Brent in the Australian horror/thriller movie
The Loved Ones in the lead role opposite
Robin McLeavy. In early 2010, Samuel was cast as Riley Biers in
The Twilight Saga: Eclipse. The film was Samuel's first high-profile film. Samuel was nominated for, and won, his first film award at the
2011 MTV Movie Awards. In an interview with
GQ Australia in November 2010, Samuel described the process of his
Twilight casting. "I sent off the audition tape from Sydney, which landed in a big pile on someone's desk. So then to actually hear something back was kind of unusual. I guess I was a bit of a gamble, but it's bizarre and wonderful." Samuel appeared as
Henry Wriothesley in the 2011 film
Anonymous. In 2012 Samuel played a lead role in
A Few Best Men with other notable stars,
Rebel Wilson and
Olivia Newton-John. The film is about a wedding. He reprised his role in the 2017 sequel,
A Few Less Men. Eventually forming a relationship with co-star
Phoebe Tonkin, Samuel was cast in 3D feature
Bait, released in September 2012. In 2013 he played Ian in
Adore beside
Robin Wright and
Naomi Watts, which is based on
Doris Lessing's book and directed by
Anne Fontaine. The film is about two middle-aged mothers who become the lovers of each other's sons. Alongside
Hugo Weaving and an owl, Samuel was cast in the movie
Healing in 2014. The film is about a prison program where the inmates rehabilitate birds. When speaking about Doris the owl, Samuel stated that he grew rather fond of her as she was easy to play with and was a real diva. In the same year, Samuel performed alongside
Kate Beckinsale,
Chloe Sevigny,
Stephen Fry, and
James Fleet in the critically-acclaimed film
Love & Friendship, adapted from
Jane Austen novel
Lady Susan. Samuel played Kit Parker in the
Amazon thriller series
Tell Me Your Secrets in 2021. In 2022, he starred in the
Marilyn Monroe bio-pic
Blonde, written and directed by
Andrew Dominik and adapted from the
2000 novel of the same name by
Joyce Carol Oates. It stars
Ana de Armas as Marilyn Monroe and premiered on
Netflix in September 2022. ==Personal life==