 Orde-Lees was educated at Marlborough College, the Royal Naval Academy at Gosport (whose headmaster was Ada's brother-in-law, Frederick George Johnson) and the Royal Military College, Sandhurst.He joined the Royal Marines, and was commissioned a second lieutenant in 1895, with promotion to lieutenant on 1 July 1896, and to captain on 16 April 1902.In 1900 he was posted to China and saw action during the Boxer Rebellion.