He was the son of John William Keeling and Elizabeth Keeling. In 1901 the family were living in house 71, South Parade, Ormeau, Belfast. They were all recorded as being of Society of Friends faith. By 1911, Keeling was residing in a boarding school at number 19.1, St. Laurence Street, St. Laurence Gate, Co. Louth. There were 4 teachers and 20 pupils in the school on Census Day 1911.
The Belfast News Letter of 8th October 1915 reporting:
There is no explanation of the age reported as 48.
The London Gazette records a 2nd Lieutenant G D Keeling relinquishing his temporary commission as of 7th May 1916.
The picture on the Roll of Honour indicates that Keeling may have been awarded the Military Medal.