Turner was born at home in Reading, Berkshire on 22 May 1893 to Charles Turner, later Major in the Royal Berkshire Regiment, and his second wife Jane Elizabeth, only daughter of Admiral Sir Alexander Buller. He was educated at Wellington College, Berkshire and commissioned into the Special Reserve of Officers, Royal Berkshire Regiment, 3rd (Reserve) Battalion, in 11 September 1914. He was subsequently transferred to 1st Battalion. His brother was Lieutenant Colonel Victor Buller Turner VC and had a family connection with General Sir Redvers Buller VC.