Anna Cecilia Petra Östergren (born 29 September 1965 in Kiruna Municipality) is a Swedish feminist writer, debater, social commentator and an instructor in self defense. She has an MA in Social Anthropology (University of Stockholm), and is a doctoral student at Lund University. Her research is titled "The State of Feminism".
In the 1980s Östergren helped launch a feminist self-defense movement in Sweden. She was active as an instructor in the organisation Pandora kvinnligt försvar (Pandora Women's Defense) and ran the Kung Fu club in the kajukenbo style in an effort to help women defend themselves against sexual assault. She was involved with the National Organisation for Women's Shelters and Roks.  She is the author of Slå tillbaka!: Handbok i självförsvar (Fight back!; A handbook of self-defence) published in 1993. She also wrote a book about her mother, who was beaten to death by a man she had had a brief relationship with, entitled Att komma till ro med det allra värsta (Coming to terms with the worst).
Sociology and gender politics
Her involvement with teaching men self-defence made her a controversial figure with radical feminists, and the rift became complete when she published an article in Bang magazine in which she questioned whether all pornography was essentially misogynous.
Östergren is considered a major critic of radical feminism in Sweden. In particular she has challenged their views on sex, violence and power, pointing out that violence in lesbian relationships did not differ significantly from that in heterosexual relationships. From its origin, Östergren was one of the few people who publicly challenged the radical feminist position on prostitution which culminated in the sexköpslagen (Sex Purchase Act) 1999. She has been an advocate for the decriminalisation of prostitution. In 2006, she published Porr, horor och feminister (Pornography, whores and other feminists), an analysis of three decades of Swedish policy on pornography and prostitution, and a critique of radical feminist sexual politics. In 2008, she published an edited volume F-ordet: Mot en ny feminism (The F -word: Towards a new feminism), bringing together writers and commentators to provide new perspectives on old feminist issues.
In addition to her books, Östergren writes regularly for newspapers and magazines, including Svenska Dagbladet, LO-tidningen, Expressen, Aftonbladet, Axess and Voltaire and regularly gives public talks, and is consulted on prostitution and gender issues.
- ISBN 9789127113961 Slå tillbaka!: handbok i självförsvar för kvinnor Natur och Kultur, 1993. Revised 1998
- ISBN 9789127063778 Att komma till ro med det allra värsta], Natur och Kultur, 1996
- ISBN 9789127113947 Porr, horor och feminister, Natur och Kultur, 2006
- F-ordet. Mot en ny feminism, Alfabeta, 2008
- Berättelsen om Esmara, (The Story of Esmara) Piratförlaget, 2010
- Brave New Man. Axess February 2010
- The Swedish Sex Purchase Act: Claimed Success and Documented Effects. S Dodillet, P Östagren. May 2011
- Synden ideologiserad. Modern svensk prostitutionspolicy som identitets- och trygghetsskapare. MA Thesis Dept. Anthropology, Stockholm University 2003
- Ulrika Oredsson. Interview with Petra Östergren - Prostitution Law, Lund University, 28 January 2010 Archived 15 August 2011 at the Wayback Machine.
- Porträtt Petra Östergren: Ofrivillig provokatör. Ulrika Oredsson 28 January 2010 Archived 16 July 2011 at the Wayback Machine.
- Roks: Riksorganisationen för kvinnojourer och tjejjourer i Sverige (National organisation for women's and young women's shelters in Sweden)