The actor will make his first appearance in the BBC medical drama in October, when his alter ego arrives in Holby suddenly and wastes no time in stirring things up.
Henrik is to be a new joint director of surgery for Holby - a role which quickly sees him locking horns with established character Connie Beauchamp (Amanda Mealing).
Guy Henry as Henrik Hanssen
Speaking of his casting, Henry commented: "I'm really enjoying playing Henrik Hanssen. It's been great joining a show as well loved as Holby City and creating a new character from scratch.
"Henrik's a bit of a mystery man - he arrives suddenly, out of the blue, placed it seems in Holby by The Department of Health to shake things up and make cuts - appropriate for a surgeon! He's punctilious, pedantic and passionate about his work.
"But he's not without a twinkle in the eye and a very dry sense of humour - essential when you have to take on Connie Beauchamp. She may have met her match!"
Reflecting on what it was like to join the cast, he added: "Actually it's been bloody frightening being the big new boy on set - but thankfully I've found Holby's reputation in the business for being a kind and friendly place to work well-justified. The cast and crew are a lovely lot."
Holby's executive producer Belinda Campbell said: "Guy is a great asset to the Holby City cast and we are very excited to have him on board. His character Henrik will make waves from his very first scene and upset the apple cart of Holby City in more ways than one."
Henry has previously appeared in a number of other TV shows, including historical drama Rome, HBO's John Adams and ITV's Lost In Austen.