The Advanced Diploma in Business Administration – Accounting program at George Brown College is designed to equip learners with critical business administration skills along with a solid grasp of accounting principles. The comprehensive curriculum covers core subjects relevant to both fields. Students learn to analyze and interpret statistical data, explore financial management strategies, understand the intricacies of corporate finance, and master tax calculation, budgeting, and auditing. They also examine matters relating to business law, economics, and information systems which are vital for their future career as business administrators or accountants. By combining theoretical knowledge with practical learning and real-world application, the program endeavors to prepare highly qualified professionals ready to take up challenging roles in industries and institutions. The advanced diploma typically spans three years of full-time study, which includes a professional work placement providing on-the-job experience. The combination of classroom instruction, lab practice, and field placement makes George Brown's program stand out for its integrated approach. It functions as an excellent stepping stone for further studies or to start a fruitful career in accounting or administration.

The college was established during the formation of Ontario's community college system in 1967. Colleges of Applied Arts and Technology were established on May 21, 1965. The college is named after George Brown, who was an important 19th-century politician and newspaper publisher (he founded the Toronto Globe, forerunner to The Globe and Mail) and was one of the Fathers of Confederation.

The college's predecessor, the Provincial Institute of Trades (PIT), was founded in 1951 to offer apprentice training on behalf of the provincial Department of Labour. In 1952, the PIT began operation at 21 Nassau Street in Toronto's Kensington Market and, after expanding with the construction of two additional buildings on the site, was offering programs in lathing and structural steel, barbering, diesel mechanics, jewellery arts, watchmaking and welding by 1961. In 1962 the province opened the Provincial Institute of Trades and Occupations (PITO), a sister training institute, at 555 Davenport Road near Casa Loma.

When George Brown College was formed in 1967, it absorbed both the PIT and PITO and opened its Kensington and Casa Loma campuses at the two institutes' former facilities. George Brown College also went on to absorb, in 1969, four former Toronto Board of Education Adult Education Centres in a third campus at 507 College Street and, in 1973, five Toronto-area Schools of Nursing in 1973, including: St. Joseph's, St. Michael's, Toronto General, Atkinson (Toronto Western) and Nightingale.

In 1973, a new expanded Casa Loma campus was opened. In 1976, the St. James Campus opened at 200 King Street East in buildings formerly belonging to Christie Bakery and Hallmark Cards.

The Hospitality building (300 Adelaide E.) opened at St. James Campus in 1987, the same year that the College Street Campus closed. Kensington Campus closed in 1994.