Brigadier-General Timothy James Grant was born in Clinton, Ontario. He attended the University of Guelph, graduating in 1977 with a Bachelor of Science degree. He subsequently enrolled in the Canadian Forces under the Direct Entry Officer programme as an armour officer.

Brigadier-General Grant has filled a number of staff positions. Most notable were Chief of Staff, Land Force Western Area and two tours in National Defence Headquarters in the Joint Operations Directorate. As J3 International he was intimately involved in the planning for Canada's contribution to the Campaign Against Terrorism, including the deployment of ground forces to Afghanistan and naval and air forces to the Persian Gulf.

He has commanded soldiers, from troop to brigade level, in Canada and with NATO in Germany. He served as the exchange officer at the Royal Australian Armour Centre. As the Commanding Officer of Lord Strathcona's Horse (Royal Canadians) he deployed his Battle Group to Bosnia in 1997 as part of the NATO Stabilization Force. He returned to Bosnia in 2000 to command the Canadian Contingent. He commanded 1 Canadian Mechanized Brigade Group from 2003 until 2005, which included the preparation and deployment of a contingent to Kabul as part of the International Security Assistance Force and the first Canadian Provincial Reconstruction Team to Kandahar.

Brigadier-General Grant is a graduate of the Command and Staff College, the Advanced Military Studies Course and the National Security Studies Course. He was invested as an officer in the Order of Military Merit in 2003. He assumed command of Land Force Western Area on 29 June 2005.