The Leader of the Opposition has been a position in the Legislative Assembly of Alberta since 1905.

Alberta has enjoyed long periods of stable government rule, and has elected massive government majority during almost every election in its history. In most other legislatures in Canada, the opposition party is traditionally recognized as a government in waiting, and will alternate periods of government among two or three parties. In Alberta however the opposition has traditionally been very small in terms of seat numbers, and highly unstable in terms of party leadership.

Peter Lougheed is the only Leader of the Opposition who has ever gone on to become Premier of Alberta.

Opposition Leaders

Conservative Leaders

• Albert Robertson (1906-1909)
• Richard B. Bennett (1910-1910)
• Edward Michener (1910-1917)
• George Hoadley (1918-1919)
• James Ramsey (1920-1920)

Liberal Leaders

• John Robert Boyle (1922-1924)
• Charles Richmond Mitchell (1925-1926)
• John C. Bowen (1926-1926)

No Leader (1926-1940)

Independent Leaders

• James H. Walker (1941-1941)
• Alfred Speakman (1942-1942)
• James Mahaffy (1943-1943)
• Alfred Speakman (2nd time) (1944-1944)
• John Percy Page (1945-1948)

Independent Citizen's Association Leaders

• John Percy Page (1948-1948)

No Leader (1949-1951)

Liberal Leaders

• James Harper Prowse (1952-1958)
• Grant MacEwan (1959-1959)

No Leader (1959-1963)

Liberal Leader

• Michael Maccagno (1964-1967)

Progressive Conservative Leader

• Peter Lougheed (1967-1971)

Social Credit Leaders

• Harry Strom (1971-1972)
  • James Henderson (acting) (1972-1973)
  • Robert Curtis Clark (acting) (1973-1975)
• Robert Curtis Clark (1975-1980)
• Raymond Speaker (1980-1982)

New Democratic Leaders

• Grant Notley (1982-October 19, 1984)
• Ray Martin (1984-June 15, 1993)

Liberal Leaders

• Laurence Decore (June 15, 1993-July 15, 1994)
• Grant Mitchell (November 12, 1994-April 17, 1998)
  • Howard Sapers (acting) (April 21, 1998-1998)
• Nancy MacBeth (1998-2001)
• Ken Nicol (March 15, 2001-March 26, 2004)
• Kevin Taft (March 27, 2004-December 14, 2008)
• David Swann (December 15, 2008-September 10, 2011)
• Raj Sherman (September 12, 2011-April 23, 2012)

Wildrose Leaders

• Danielle Smith (April 24, 2012-December 17, 2014)
• Heather Forsyth (December 23, 2014-May 5, 2015)
• Brian Jean (May 5, 2015-Present)