Grant Thornton International had its origins in 1904 with the firm Thornton & Thornton from Oxford, UK. Twenty years later and across the Atlantic, at the age of 26, the accountant Alexander Richardson Grant formed Alexander Grant & Co in Chicago, United States.

In the mid-1960s, company management decided that the time was right to expand internationally. In 1969, with Wallace E. Olson at the helm, Alexander Grant & Co. joined companies from Australia, Canada and the United Kingdom to establish Alexander Grant Tansley Witt. This organization functioned successfully for 10 years.

By 1980, Alexander Grant & Co. joined with 49 other accounting firms, including Thornton Baker in the UK, a firm with similar qualities, clients, staff numbers and values, to form a global organization, Grant Thornton International. Following its merger with Denver-based Fox & Co. in 1985, Alexander Grant & Co. became the ninth-largest accounting firm in the United States, behind the "Big Eight" group of firms at the time. . In 1986, Alexander Grant & Co. changed its name to Grant Thornton, reflecting its affiliation with the British firm Thornton Baker, which also changed its name to Grant Thornton.

In 2001, the Adler, Hasenclever & Asociados firm, headquartered in Buenos Aires, joined Grant Thornton International, giving rise to Grant Thornton Argentina. The firm began its operations in the local market with the aim of assisting in the development and strengthening of companies and public entities, through the application of professional policies and practices established by the international network.

In 2011 Grant Thornton Argentina acquired Associated Auditors and Sergio Kriger & Asociados, achieving a strong specialization in auditing, taxes and consulting for the financial and foreign exchange markets. In 2016, the consulting firm Consulting Partners specialized in E-Learning and people management joined the firm.

Grant Thornton Argentina has more than 50 years of experience in the local market, offices in the City of Buenos Aires with a human capital of more than 350 collaborators, an office in Córdoba and a current team of strategic alliances in the provinces of Mendoza, Tucumán and Santa Fe.

Grant Thornton International, more than a century after its birth, has become a global network of firms with more than 56,000 collaborators and a presence in 140 markets.