Cameron was born on 13 September 1894 in the Sydney suburb of Balmain North. He was the second child of Anglican clergyman Ronald John Cameron and his wife Lilly Wafford. Cameron was educated at the Sydney Church of England Grammar School between 1908 and 1912. He was initially employed by Dalgety & Co. as a junior clerk.
Cameron served in the Australian Militia before the war, having initially been involved in the senior cadets. Following the outbreak of the First World War, Cameron volunteered for overseas service, enlisting in the Australian Imperial Force on 18 March 1915. He was promoted to sergeant two months later while serving with the 20th Battalion. Cameron fought during the Gallipoli Campaign between August and December 1915 and was made company sergeant major in February 1916 while in Egypt following the battalion's withdrawal from the peninsula. Transferred to France with the 20th Battalion, Cameron was commissioned on 16 August 1916. He received a shoulder wound near Flers on 15 November and was promoted to lieutenant the next day. After being evacuated to England, Cameron arrived back on the front on 1 September 1917, but received a thigh wound during the Battle of Menin Road on 20 September. Cameron was again evacuated to England and returned to the 20th Battalion's lines two months later. Now a company commander, Cameron attacked an enemy strongpoint with an NCO, killing several German soldiers and capturing two machine guns on 8 August 1918 during the Battle of Amiens. Cameron also held his assigned positions with 12 men against a German assault. For these two actions, Cameron was awarded the Military Cross. During an attack on 3 October near Beaurevoir in one of the final actions fought by the AIF during the war, Cameron took charge of forward units of his battalion and consolidated the flank of the brigade assault, for which he received a Bar to his Military Cross. Cameron returned to Australia in April 1919 and was demobilized on 2 June.
Inter-war years
Cameron began farming and later became a pay clerk at Sydney Ferries Limited in 1923. Cameron also rejoined the Militia the same year and was promoted to Captain the next year. He married Aline Vindin on 14 August 1924 at St. James's Church of England. In 1929, he was promoted to major. Cameron became a lieutenant colonel in July 1933 and commanded the 18th Battalion until 1940. Cameron became an accountant at Sydney Ferries Limited in 1934. He was also the mayor of the municipality of Kuring-gai in 1936.
Second World War
In May 1940, he became the commander of the 8th Brigade. Made a temporary brigadier in January 1941, Cameron was called up on 10 March and he subsequently led the brigade during garrison duties in Western Australia where they were deployed to respond in the event of a Japanese invasion. He transferred to the Second Australian Imperial Force in August 1942. The 8th Brigade landed at Finschafen in January 1944, and took part in the final stages of the Huon Peninsula campaign. During the pursuit of the Japanese towards Madang, the brigade killed 734 Japanese and took 48 prisoners, losing three killed and five wounded, before reaching Madang in April 1944. Two months later, Cameron relinquished command and transferred to the 2nd Brigade in New South Wales from then to December 1944. Cameron was transferred to the Reserve of Officers on 27 February 1945 as an honorary brigadier. He was also mentioned in despatches for New Guinea service.