Herbert Spencer Clark was born on October 10, 1903 to John Ernest Clark (March 8, 1864-February 1, 1945) and Esther Louisa Alexander (January 15, 1865-January 31, 1943). He was raised alongside his four siblings; John Alexander Clark (October 23, 1891-September 23, 1950), Samuel Ernest Clark (September 11, 1894-1961), Florence Mabel Clark (June 12, 1896-December 1, 1972), and Wilfred Harold Clark (August 8, 1905-April 21, 1982).

As a young adult, Spencer graduated from the University of Toronto School of Applied Sciences in 1924, and pursued an engineering career for several years, most notably with the Ontario Hydro Electric Power Commission in building the Queenston-Chippewa Power Station.

In the summer of 1931, Spencer visited Europe as part of a study group led by Dr. Sherwood Eddy. Members of the group observed social and economic conditions in the major nations of Europe, including the Soviet Union.

While organizing the Robert Owen Foundation in Toronto with Professor Henri Lassere of the University of Toronto, Spencer met this future wife, Rosa Melvina Breithaupt Hewetson Clark. Spencer married Rosa on August 7, 1932. During that same year, Spencer and Rosa purchased property in Scarborough, Ontario and founded the Guild of All Arts, one of the earliest Canadian co-operative communities of artists and creative workers. Subsequently, Spencer's activities expanded to include a key role in the development of Guildwood Village and the transformation of the Guild from a centre for artists and craftsmen during the pre-war period to a hotel and conference centre following the Second World War. In the 1960's and 70's, his focus shifted once more, this time to the area of public sculpture, architectural conservancy and preservation.

Throughout his life, Spencer was a prolific correspondent and diarist.

Herbert Spencer Clark died on February 11, 1986.