Henry Seymour Tobin OBE DSO was born at Ottawa Ontario (ON), son of Seymour Tobin of Halifax Nova Scotia and Laleah Ann (Crawley) Tobin of Wolfville N.S. He was educated at Ottawa College and the Royal Military College, Kingston ON. He was called to the Bar of Yukon in 1902 and to the Bar of Alberta in 1908 and the Bar of British Columbia in 1910. In WW1, Tobin served overseas and commanded the 29th (Vancouver) Battalion.

Lieutenant Colonel Tobin was "Mentioned in Despatches" and was awarded the Distinguished Service Order (DSO) for great gallantry and devotion to duty in operations near Cambrai France, on the 9th, 10th and 11th of October 1918. His citation reads, in part, as follows: He went forward with advancing troops, directed their movement under heavy fire, and greatly contributed to the success of the operation. Later, when his troops were held up by heavy fire in a swamp, he went forward, reorganized them, and secured valuable information, which materially assisted in the ultimate success of the operation.

After WW1, Tobin practiced law in Vancouver B.C. as a partner in the firm of Tobin, Tarr & Ross. He became President of the Canadian Manufacturers Association. Tobin was also President of West Coast Industries Ltd., a British Columbia Crown Company making machine tools during World War 2. He also became President and General Manager, Vancouver Breweries Ltd., and president and director of several other Vancouver companies. In July 1930 he married Margaret Taylor, daughter of Mr. and Mrs. E.O. Taylor.