Sidney Hope Dobell DSO CA was born in Québec City, Québec, son of William Molson Dobell and Constance May (Sewell) Dobell. He was educated at Royal Military College, Kingston, Ontario and at McGill University School of Commerce, where he received his CA degree. In WW1, Dobell served overseas as a Lieutenant in the British Army during 1918 and 1919. Prior to WW2 he was Senior Partner in McDonald, Curry & Company, Chartered Accountants.

In 1940, he was posted overseas in command of the 5th Battery of the 1st Canadian Division. In July 1941, he was promoted to Lieutenant Colonel and posted to command No. 3 CARU. In December 1941, Dobell was promoted to Colonel with the 6th Field Regiment, Royal Canadian Artillery, 2nd Canadian Division. He was awarded the Distinguished Service Order (DSO) for distinguished service and gallantry in action and was demobilized in November 1945.

From 1947 to 1955 Dobell was Executive Assistant to the Principal of McGill University, Montreal, Québec. Next, he joined B.J. Coghlin Ltd., manufacturers of railway springs and supplies, hydraulic equipment and pumps, where he rose to become President and Director of the firm. In 1925, he had married Mary Grant McIntosh. They had two sons; Peter and William. His second marriage was to Margaret Monchamp (Elliott) Vincent, widow of Commander L.A. Vincent.