Born Carmel Brickman, she came from a Jewish family in London, whose anti-fascist beliefs influenced her left-wing politics. She received a bachelor's degree in Economics in 1946 from the University of London, where she became active in the National Union of Students. While working in Prague for the International Union of Students, she met Suwondo 'Bud' Budiardjo, an Indonesian government official whom she married in 1950. The couple moved to Indonesia in 1951, and she became an Indonesian citizen in 1954. She worked first as a translator for Antara, the Indonesian news agency, then in economic research for the Ministry of Foreign Affairs, later studying at the University of Indonesia's School of Economics and then lecturing at Padjadjaran University in Bandung and Res Publica (now Trisakti) University in Jakarta.
After General Suharto seized power in 1965, her husband was imprisoned, spending 12 years in jail. She herself was arrested, and later imprisoned in 1968 for three years, and was then deported to England on her release in 1971.
Upon returning she founded Tapol to campaign for political prisoners in Indonesia, which took its name from the abbreviation of tahanan politik, or "political prisoner" in Indonesian. The organisation expanded its activities, and was prominent in getting out information on military activity and human rights violations in East Timor, invaded and occupied by Indonesia in 1975, as well as West Papua and Aceh. The Tapol Bulletin was a major source of information about the human rights situation in Indonesia under the New Order. She is also the author of a number of books on human rights and politics in Indonesia. The organisation remains active, with Budiardjo still playing a very important part in its activities.
- Budiardjo, Carmel. "The Abuse of Human Rights in Indonesia" in W. A. Veenhoven ed. "Case studies on human rights and fundamental freedoms: a world survey", Volume 3. The Hague: Martinus Nijhoff, 1976.
- Budiardjo, Carmel and Liem Soei Liong. The War against East Timor. London: Zed Books, 1984. ISBN 0-86232-228-6.
- Budiardjo, Carmel and Liem Soei Liong. West Papua: The Obliteration of a People. Rev. ed. Thornton Heath, UK: TAPOL, the Indonesian Human Rights Campaign, 1988.
- Budiardjo, Carmel. Surviving Indonesia's Gulag: A Western Woman Tells Her Story. London: Cassell, 1996. ISBN 0-304-33562-2.
- Rights activist says genocide continues in Indonesia, JWeekly, Saturday, 26 October 1996
- The Cultural Cold War in Western Europe, 1945–60, Hans Krabbendam, Giles Scott-Smith, Routledge, 2004, page 117
- The International Union of Students, Paul Francis Magnelia, Peninsula Lithograph Company, 1967, page 75
- Development Policy and Law Seminar, 1973–1974, Volume 3, Kenneth F. Phillips, Earl Warren Legal Institute, University of California, School of Law, 1974, page i
- Surviving Indonesia's Gulag: A Western Woman Tells Her Story Carmel Budiardjo, Cassell, 1996, page 130
- British woman narrates account of prison torture Archived 21 June 2015 at the Wayback Machine., The Jakarta Post, 12 September 1999
- Sukarno Plot: British Woman Held, Glasgow Herald, 14 December 1965
- I'll campaign for Timor until I die, The Independent, 25 October 1998
- Human rights campaigner Carmel Budiardjo made an honorary Papuan, Scoop, 12 January 2011
- What is the TNI's Aceh agenda?, Inside Indonesia 76: Oct – Dec 2003
- Right Livelihood award: 1985 – Carmel Budiardjo