Although born in Shropshire, he spent his early childhood on UK military bases in Britain and Germany.

[citation needed] The road trip documentary film follows Blackthorne and Australian photographer Mister Basquali as they travel across America interviewing everyday Americans about how they feel about their country and their hopes for its future.

[2] In 2002, Blackthorne portrayed British doctor Matt Slingerland on Presidio Med and made appearances as Guy Morton in the British television series Holby City, Liam MacGregor in Peak Practice, Doctor Jeremy Lawson in NBC's ER and biological terrorist Stephen Saunders on 24.

Also on 7 December 2010, he appeared in the Christmas episode ("Secret Santa") of the SyFy series Warehouse 13.

He starred as Clark Quietly in the ABC paranormal/adventure/horror television series The River about a group of people on a mission to find a missing TV explorer in the Amazon.

In 2012, Blackthorne joined the main cast of The CW superhero drama series Arrow as Detective Quentin Lance.