Lowe was appointed to the Supreme Court of Victoria in January 1927, with the encouragement of his friend Owen Dixon. He notably presided over the trial of the accused Pyjama Girl murderer in 1944 and the murder trial of John Bryan Kerr in 1951, where his decision was upheld on appeal to the Judicial Committee of the Privy Council. He also presided over "four major commissions of inquiry" – the 1940 inquiry into the Canberra air disaster, the 1942 inquiry into the Bombing of Darwin, the 1943 federal royal commission into Eddie Ward's "Brisbane Line" allegations, and the 1949–1950 Victorian royal commission into the Communist Party of Australia. In the latter, communist activist Ralph Gibson concluded that "contrary to our fears and to the Government's hopes, displayed a certain genuine interest in Communist theory and a certain respect for evidence".