He was a Minister of the Crown in the province of Alberta and worked on agricultural projects after leaving politics.
Parliament would be dissolved a year later after the minority government fell forcing the 1963 federal election.
He defeated incumbent William Patterson in a closely contested race to win the district.
Horner ran for a fourth term and won his largest provincial plurality in the 1979 Alberta general election.
His brother Jack Horner served as a Member of Parliament and Minister of the Crown in Alberta from 1958 to 1979.
His son, Doug Horner, followed his footsteps to become Alberta's minister of agriculture in 2004 and went on to become deputy premier in 2010.