The 173rd (Highlanders) Battalion, CEF was a unit in the Canadian Expeditionary Force during the First World War. One of a number of Highlander battalions in the Canadian Expeditionary Force, it was based in Hamilton, Ontario and began recruiting during the winter of 1915/16. The unit sailed to England in November 1916. On January 17, 1917, it arrived at Bramshott where on January 19 it became part of the 2nd Reserve Battalion of the 6th Reserve Brigade. The 2nd Reserve Battalion was designated to supply drafts for the 125th and 116th Battalions, CEF. The 173rd (Highlanders) Battalion had one Officer Commanding: Lieut-Col. W. H. Bruce.