In WWI the regiment provided 290 other ranks to the 5th (Western Cavalry) Battalion on its formation at Camp Valcartier in August 1914. The 5th Battalion sailed with a strength of 1564 personnel well over the usual 1050 CEF Infantry Battalion establishment. After its arrival in the UK the 16th CLH personnel were assigned to the Canadian Cavalry Depot where in December 1915 they were designated the 3rd Divisional Cavalry Squadron (16th Canadian Light Horse) this authorized Under General Order 151 of December 22nd 1915.
