The leader of the Official Opposition, formally known as the leader of His Majesty's Loyal Opposition, is the member of the Legislative Assembly (MLA) who leads the Official Opposition, typically the second largest party in the provincial legislature.

The Progressive Conservative Association of Alberta was a provincial centre-right party in the Canadian province of Alberta that existed from 1905 to 2020. The party formed the provincial government, without interruption, from 1971 until the party's defeat in the 2015 provincial election under premiers Peter Lougheed, Don Getty, Ralph Klein, Ed Stelmach, Alison Redford, Dave Hancock and Jim Prentice. At 44 years, this was the longest unbroken run in government at the provincial or federal level in Canadian history.