Dave Hancock is now officially the 15th premier of Alberta.
Hancock took the oath of office in front of fellow caucus members and guests in a ceremony at Government House on Sunday evening.
Minutes before taking the oath, caucus whip George VanderBurg formally submitted Alison Redford's resignation as premier.
Hancock was voted by caucus to take over from Redford after she resigned Wednesday amid caucus turmoil.
He will serve as premier until the Progressive Conservatives select a permanent replacement in the coming months, but says he himself will not be a candidate.
Party officials meet Monday in Red Deer to set out the details for the race.