Ms Adamson took the oath as the state's 36th governor at a ceremony at Government House in Adelaide on Thursday.

She replaces Hieu Van Le, who served in the office from 2014 and becomes the third woman to hold the role.

She recently completed a term as the secretary of the Department of Foreign Affairs and Trade.

Premier Steven Marshall said Ms Adamson came to the position after completing three-and-a-half decades of distinguished public service in Australia.

"She is a very proud South Australian with a plethora of experience in international affairs, vitally important to South Australia as we recover from the once-in-a-century COVID-19 pandemic," Mr Marshall said at the time of her appointment.

"Her wealth of knowledge on the international stage will put South Australia in good stead as we continue to put South Australia on the global map."

Ms Adamson said she felt a deep sense of honour and privilege when she was first approached to take up the appointment.

"I am greatly looking forward to returning home to serve the people of South Australia and contribute to the state's international engagement through the promotion of trade, investment and people-to-people links," she said earlier this year.

Australian Associated Press