Hakewill-Smith was born in Kimberley, Northern Cape, South Africa, on 17 March 1896. He was educated at the Diocesan College ("Bishops") in Rondebosch, Cape Town, and, during the First World War, he went to England to attend the Royal Military College, Sandhurst, where he was commissioned as a second lieutenant into the Royal Scots Fusiliers, a line infantry regiment of the British Army, on 16 June 1915. He served with the 2nd Battalion of his regiment on the Western Front, where he was wounded twice and, during the final Hundred Days Offensive in the latter half of 1918, and was awarded the Military Cross. The citation for the award read: