Cameron was born in Happy Valley, South Australia. After serving in World War I, he became took up a farm near Loxton as a soldier settler. He was elected to the South Australian House of Assembly in 1927, and to the House of Representatives at the 1934 federal election. Cameron was Postmaster-General in the Lyons Government from 1938 to 1939. He replaced Earle Page as leader of the Country Party in September 1939, and in March 1940 led the party back into coalition with the United Australia Party (UAP), which Page had broken off. Cameron was "de facto" deputy prime minister under Menzies, as well as Minister for Commerce and Minister for the Navy. However, he was deposed as Country Party leader in October 1940, subsequently defecting to the UAP (and later joining the new Liberal Party). Cameron's last appointment was as Speaker, where he was highly respected. He was known throughout his political career for his eccentric manner and strong personality.