The 35-year-old replaces Hand, who stepped down after less than two years in charge at the back end of June, and will take charge of his first game in September.
He makes the step up from assistant coach, a position he held since 2012, and will combine the role with his new job as coach of Elite League side Sheffield Steelers.
And a proud and excited Christiansen can't wait to put his vision into place and see it thrive, determined to get more young players participating to the benefit of the national team.
"Being named GB coach is the biggest honour of my hockey career. I am absolutely thrilled by the appointment," said Christiansen.
"I would like to thank Tony Hand for all of his efforts the last two seasons. I learned a lot from him and it was a privilege to work for him.
"Hockey in Great Britain is at a crossroads. It is my vision to help push GB forward building a world-class program.
"The IHUK board are excited about pushing the game forward and aspiring to be like Switzerland or Norway.
"Both nations that have created long-term strategic plans with tangible goals and realistic aspirations.
"Both have made an investment in the youth, while pushing the national team to new heights.
"Our goals will be high. Our intent is to set a path that can be followed from the age of 16 to the top. I am excited about what we can achieve.
"We know there will be bumps in the road and, at times, resistance but our ambition is to learn from Norway, Korea, Japan and Switzerland, so that we can improve our game and as a result see more kids playing the best game in the world."