Henry was the son of William and Catherine Garrett of Inverell where his birth was registered in 1883. He was a thirty two year old Shearer when he enlisted at Inverell in October 1915. He joined the 4th Battalion, 18th Reinforcement and left Australia on the ship HMAT A55 Kyarra in June. After a bout of illness in England he was sent to France in March 1917 where he was twice wounded in action, including a gunshot wound to his face.
Henry returned to Australia in May 1918 and was medically discharged with a pension of thirty shillings ($3) per fortnight. He returned to Inverell where he committed suicide in 1924.
Private Henry Garrett has his name recorded on the Inverell Honor Roll and Cenotaph.