The 18th Alberta Legislative Assembly was in session from May 15, 1975, to February 14, 1979, with the membership of the assembly determined by the results of the 1975 Alberta general election held on March 26, 1975. The Legislature officially resumed on May 15, 1975, and continued until the fourth session was prorogued on November 3, 1978 and dissolved on February 14, 1979, prior to the 1979 Alberta general election on March 14, 1979.