Foyle DUP MLA Gary Middelton has been named as a Junior Minister by his part leader.
Mr Givan will be joined in the new DUP Ministerial team from next Monday by Michelle McIlveen, who is to be the new Education Minister and Paul Frew, who will take over the Economy portfolio from Diane Dodds.
Mr Poots announced the new senior posts at Stormont on Tuesday.
Mr Givan Tweeted this afternoon: “I am privileged and humbled to have the opportunity to serve our people in the days ahead.
“When I first entered politics I never believed I would follow in the footsteps of Dr Paisley, Peter Robinson and Arlene Foster.
“I am indebted to their service and sacrifice.”
Dianne Dodds Teweeted earlier today: “Unionism can only grow if it is generous, inclusive and encourages as many pro-Union voters to the cause as possible. I will continue in my efforts to safeguard the Union and make Northern Ireland the best place to live, work and invest.”