Born in Hāwera, Grant was a builder when he volunteered in June 1915 to serve in the First World War with the New Zealand Expeditionary Force (NZEF). He was posted to the 1st Battalion of the Wellington Regiment which began its service on the Western Front in 1916. It was on 1 September 1918, during an engagement at Bancourt, France, that he attacked two machine-gun posts, which led to him being awarded with the VC. He ended the war as a second lieutenant. Discharged from the NZEF, he returned to civilian life and then joined the Territorial Force. In his later years, he struggled to hold down regular employment due to the effects of what was most likely post-traumatic stress disorder. He died in 1970 at the age of 81.