Harvey Ennis Gale was born on 19 November 1896 in Maclean, New South Wales, to May (née Ennis) and Arthur Gale. He served in the Cadets in his youth and later worked as a farmer. At age 18, Gale enlisted for service in the Australian Imperial Force (AIF) in Lismore, New South Wales, on 13 October 1915.

Allotted to the 16th Reinforcements to the 9th Australian Infantry Battalion, Gale embarked from Sydney for overseas service on 31 March 1916 aboard HMAT Star of Victoria. He disembarked in Egypt before being posted to France from June. Gale was wounded in action twice while serving on the Western Front, suffering back contusions and shell shock in September 1916, and a gunshot wound to his forearm in April 1918. He returned to Australia in early 1919 and was discharged from the AIF as a corporal on 10 May.

Returning to civilian life, Gale was appointed a health inspector for the Harwood Shire Council from 10 November 1920. The following June, he married Lily Walter in Queensland. By the 1930s, the Gales were living on Corrimal Street in Wollongong, where Harvey continued to work as a health inspector and served on the advisory committee for the Wollongong Technical College. In recognition of his "public services", Gale was appointed a Member of the Order of the British Empire (Civil Division) in the 1939 New Year Honours.

Having served as a lieutenant in the 34th Battalion, Citizen Military Forces since 1936, Gale was mobilised following the outbreak of the Second World War. He was commissioned a lieutenant in the 2/3rd Australian Infantry Battalion, Second Australian Imperial Force in November 1939 and, the following January, embarked for overseas service. He served in the Middle East until 1942, having been promoted to major in November 1941, Mentioned in Despatches, and assumed positions of increasing responsibility.

Gale spent much of the remainder of the war as a camp commandant in Australia, New Guinea and on Bougainville. In 1945, he was appointed an Officer of the Order of the British Empire (Military Division) in recognition of his "Skill & untiring devotion to duty".

Following the end of the war, Gale was appointed to the headquarters of the British Commonwealth Occupation Force (BCOF) in Japan from 14 December 1945. He was promoted temporary lieutenant colonel on 1 August 1946 and subsequently appointed Area Commander of Eta Jima.

During a recreational duck hunt near Akitsuki, Eta Jima, Japan, on the morning of 29 February 1948, Lieutenant Colonel Gale was shot and killed when a 12-bore shotgun was accidentally fired at close range. He was accorded a military funeral and is buried in Yokohama War Cemetery, Japan.