Tarja Kaarina Halonen (1943-), a Finnish politician and the President of Finland from 2000 to present.

She was a member of parliament 1984-2000, the Minister of Social Affairs and Health 1987-1990, the Minister of Justice 1990-1991, the Minister for Nordic Cooperation 1989-1991, and the Minister for Foreign Affairs 1995-2000. She was a member of the Finnish Social Democratic Party 1971-2000. In 1974 she was appointed parliamentary secretary to the Prime Minister, a post she held until 1975.

She is Trade Union lawyer by training. She married her long time common-law partner, Dr. Pentti Arajärvi, after she was elected president.