Thomas Clarkson,, was an English Canadian merchant, banker, businessman, receiver, director, and associated with the Family Compact, although was noted for his desire to increase free trade relations with the United States whom he described as "Canada's most important traders and partners", even advocating for an ambassador be sent to D.C. to exert "some active, intelligent, and influential representation of the commercial interests of Canada near the controlling power of the United States" and reciprocity with the British West India Island. He established the trustee and receivership business which would eventually become Clarkson Gordon in 1864 and was a founder, incorporator and first president of the Toronto Board of Trade, president of the Commercial Building and Investment Society, director of the Beacon Fire and Life Insurance Co. of London, the Toronto for Unity Fire Association with Allan MacNab, Federick Jarvis, and Benjamin Cronyn, and the Bank of Toronto where he additionally served as vice president in 1859.

Clarkson Gordon was a national Canadian accounting and receivership business founded in Toronto, Upper Canada in 1864 by Thomas Clarkson and operated for 125 years until the partnership elected to merge with the EY network of firms in 1989 following the merger between Ernst & Whinney and Arthur Young & Co.