Harry Atherton was born on 15 November 1893 in Leigh, England. He was the son of James Henry Atherton and Sarah Atherton (née Ball). Atherton grew up in Tyldesley, England and moved to Canada in 1913 by himself. He settled in McBride, British Columbia and worked as a carpenter before enlisting.

On 31 March 1916, Atherton enlisted in the Canadian Expeditionary Force (CEF) with the 63rd Canadian Infantry Battalion (Edmonton), CEF in Edmonton, Alberta at the age of 23. On 22 April 1916 Private Atherton left the port of Saint John, New Brunswick, bound for England and arrived in Liverpool thirteen days later. 

Upon arrival, he was transferred to the 9th Reserve Infantry Battalion, CEF which absorbed the 63rd Battalion. 

After spending several months in the Shorncliffe Military Camp, Private Atherton arrived in France on 18 July 1916 after having been transferred the day before to the 10th Canadian Infantry Battalion, CEF. Upon his arrival, Private Atherton fought in several battles before being wounded. Due to his injuries, Atherton was sent to England to recover for a few months before returning to the front in March 1917.

On 15 August 1917, Private Atherton fought with the 10th Battalion during the first day of the Battle of Hill 70. The assault had two main objectives, the positions known as the "Blue Line" and the "Green Line”. The 10th Battalion, being part of the 2nd Canadian Infantry Brigade, took part in the first assault for control of the "Blue Line". This objective was achieved, and the 10th Battalion led the continued advancement to the "Green Line". 

This objective was seized early in the morning of 16 August. From 14 to 18 August 1917, the 10th Battalion suffered 429 casualties, 71 with no known graves in connection to the assault on Hill 70. Private Atherton's service and medical records initially list him as wounded. In later reports he is stated to have been killed in action on 15 August 1917 at the age of 24.

Following the war, Private Atherton's name was engraved on the Canadian National Vimy Memorial. This memorial commemorates Canadian soldiers who died during the First World War and have no known grave.

On 11 July 2017, human skeletal remains were discovered during a munitions clearing process near rue Léon Droux in Vendin-le-Vieil, France. An insignia of the 10th Battalion and an illegible identification disc were found with the remains by the CWGC Recovery Unit. 

The identification disc was sent to the Canadian Conservation Institute where they were able to clean it. After the cleaning process, “10 BATT” was clearly visible at the bottom of the identification disc. The numbers “4 - - 658” showed a service number and on the upper right border of the disc, “ON” was visible. This information greatly helped to identify Private Atherton.