In 1946, Court joined the Liberal Party and stood in 1953 as one of two co-endorsed Liberal candidates in the Perth metropolitan seat of Nedlands. After distribution of preferences, he received 54% of the valid votes. He would hold this seat for just over 29 years. He became a member of the opposition until the election of a Liberal government in 1959, and was elevated to cabinet as Minister for Industrial Development under (Sir) David Brand. He held this post until the Liberal-Country Coalition was defeated at the 1971 election. In May 1972, Brand retired as opposition leader for health reasons and was replaced by Court. In 1974, the Liberal-Country Coalition defeated John Tonkin's Labor government and Court became premier.