Geoffrey Walsh was born in Brantford ON. He was educated at St. Catharines Collegiate, where he was a member of the school cadet corps, the Royal Military College, Nova Scotia Technical College and McGill University. He joined the Lincoln Regiment as a private soldier in 1924 and attended annual training in that year and the two following years. He entered the Royal Military College in 1927. He graduated in 1930 and was commissioned into the Royal Canadian Engineers and served in the Permanent Force. He transferred to the Active Force in 1939.
He had a distinguished record during the Second World War. Shortly after the war began he took command of 'B' Company in the newly formed 1st Pioneer Battalion, RCE in Toronto and soon moved with the battalion to Aldershot in England. When Number 1 Canadian Engineer Holding Unit was set up to receive reinforcing troops from Canada, Major Walsh was appointed Chief Instructor. He later took command of the 3rd Field Company and led them through the Spitzbergen operation in August 1941. In November he moved to RCE 1st Canadian Corps Troops and in February 1942 he was promoted to Lieutenant and appointed Commander 1st Canadian Infantry Division Engineers (CRE). In early April 1943, he joined Lieutenant-General Guy Simonds in London as part of the Allied planning staff for the invasion of Sicily planned for that summer.
Lieutenant-Colonel Walsh was among the first to land at Pachino Beach and made certain he was forward with his engineer companies as much as possible. On 21 July during the attack on Leonforte and the building of the Bailey bridge by the 3rd Field Company, he spent a fair amount of time on-site under fire while the sappers pushed their bridge over the ravine in less than four hours. While leaving the troops to do their jobs, he provided direction to ensure they had everything they needed to succeed despite the enemy being as close and 50 yards from the bridge site and there being no infantry protection. This was the first Bailey bridge build under fire during the war, and without it, the capture of the town of Leonforte would have been delayed considerably with repercussions not just to the Canadian advance but to the US Army advance to their left. General Simonds recommended an immediate award of the Distinguished Service Cross befitting his rank and his courage under fire.
Geoffery Walsh continued to serve during the war and after, retiring in 1966. During that time he was CRE 1st and 4th Divisions, Commander Northwest Highway System. Commander 27th Canadian Infantry Brigade Group in Germany, General Officer Commanding Western Command, and Chief of the General Staff, and Vice-Chief of the Defence Staff. During retirement he served as Colonel Commandant of the Royal Canadian Army Cadets from 1970 until 1974 and while in that position, organized the Army Cadet League of Canada.
He died in Ottawa in 1999 at the age of 90 years.
During the assault of 2 Canadian Infantry Brigade on Leonforte, 21/22 July 1943, it was essential that an enemy demolition be bridged in order that supporting arms for the brigade could be moved forward. The bridging site at the time was under heavy enemy machine gun and mortar fire. The operation was done in the dark by 3 Canadian Field Company, but owing to the vital importance of this bridge, Lieutenant-Colonel Walsh as Commander Royal Engineers personally supervised the effort. Some 40 Germans and three German tanks were within 50 yards of the bridging site rendering it almost impossible for infantry to secure covering positions. Lieutenant-Colonel Walsh ignored the incessant small arms fire which ricochetted off the bridge members, rushed through the construction, and as a result, the bridge was open for traffic at 0210 hours, well in advance of schedule, enabling the necessary supporting arms to cross and conclude the successful drive on Leonforte.