• Chairman of the Swedish Social Democratic Party Mona Ingeborg Sahlin, 1957

Sahlin has been a Member of Parliament, representing Stockholm County, from 1982 to 1996 and again since 2002. She has also held various ministerial posts in the Swedish government from 1990 to 1991, from 1994 to 1995 and from 1998 to 2006. Sahlin was elected new leader of the Social Democratic Party on 17 March 2007, succeeding Göran Persson who resigned as leader following the defeat in the 2006 general election. Sahlin is the first female leader of the Swedish Social Democratic Party and the only one never elected Prime Minister together with Claes Tholin and Håkan Juholt.

On 14 November 2010, following another electoral defeat for the socialist parties, she announced her intent to step down as party chairman in early 2011.

Sahlin was born Mona Ingeborg Andersson in Sollefteå, Västernorrland County, Sweden. Her father, Hans Andersson, worked at different ungdomsvårdsskolor (community homes or reformatories), forcing the family to move frequently. In the mid 1960s they moved to Järla in Stockholm County where they remained. Her father later became an advisor to former Prime Minister Ingvar Carlsson.

In 1964, at the age of seven, Sahlin founded the Swedish "Barbie Club" (Barbieklubben). During her childhood she also enjoyed soccer and music. In Melodifestivalen 1969 (the selection for the song to represent Sweden at the 1969 Eurovision Song Contest) Sahlin performed as one of the back up singers to Jan Malmsjö. The song was written by Benny Andersson and Lasse Berghagen and it came in second place.

Sahlin was educated at Nacka Samskola and Södra Latin in Stockholm and completed secondary school in 1977. From 1976 to 1977 she was vice chairperson of the Swedish Pupils' Association (Swedish: Elevförbundet). Thereafter she worked at a private company and later as a trade union representative for the Swedish National Union of State Employees.

Sahlin's political career began in the Swedish Social Democratic Youth League in Nacka, Stockholm County, in 1973, at the age of 16. This was during the Vietnam War, and already as a 13 year old Sahlin had joined the Swedish FNL group.

In the Swedish general election of 1982 Sahlin was elected to the Riksdag as the youngest member of parliament at that time. In 1990, she became Minister for Employment, but after the Social Democrats lost power in the 1991 election, Sahlin began to serve as chairman of the Riksdag's Committee on the Labor Market and as spokesman for the Social Democrats on labor market issues. From 1992 to 1994 she was party secretary, a post she left to rejoin the government as Minister for Gender Equality and Deputy Prime Minister, when the Social Democrats regained power in the 1994 election.

From 1996 to 1997, Sahlin worked as a self employed owner of a small company and as a television reporter. In 1997 she was elected chairman of the European Council Against Racism and in 1998 she became the head of the Social Democratic youth education school Bommersvik.

Sahlin returned to national politics in 1998, when then Prime Minister Göran Persson appointed her as Minister without Portfolio. She served first in the Ministry for Industry, Employment and Communication from 1998 to 2002, then from 2002 to 2004 in the Ministry of Justice as "Minister for Democracy and Integration", and from 2004 to 2006 in the Ministry of Sustainable Development as "Minister for Sustainable Development".

After the Social Democratic defeat in the 2006 election, Göran Persson announced his retirement as party leader on the election night. It was clear that the party now wanted a female leader. Mona Sahlin was mentioned as a possible successor, but not considered to be the most likely candidate. Both Margot Wallström and Carin Jämtin received stronger support amongst local and regional party organizations. Ulrica Messing was also mentioned as a possible candidate. Wallström, Jämtin and Messing declared however that they would not stand for the post and instead supported Sahlin, leaving Mona Sahlin as the only serious candidate. On 18 January she was officially asked by the party's Election Committee to stand as party leader, and accepted. On 17 March she was unanimously elected at the extra party congress in Stockholm.

In January 2007, support for the new center right government of Sweden had dropped greatly in the polls, which showed the left bloc (including the Green Party) as having much stronger support. This provided Mona Sahlin, as leader of the biggest opposition party, with excellent opportunities to lead the opposition against PM Fredrik Reinfeldt. By April 2009 however, the support had waned and a Demoskop poll published in Expressen showed the four party Alliance claimed a combined 50 percent voter support while the Sahlin lead opposition had 45.2 percent. Later the same month a Sifo poll showed just 27 percent of Swedes confident or extremely confident in her leadership ability, while support for Reinfeldt was 60 percent.

Mona Sahlin is often described as a scion of the party's more moderate members, and a number of left wing party members criticized her candidacy for party leader. Much of this criticism was silenced in January 2007 when the chairman of the Trade Union Confederation, Wanja Lundby - Wedin, expressed full support for Sahlin as well as several powerful party districts around the country.

In the election to the European Parliament held on 7 June 2009 – Sahlin's first election as party leader – the Social Democratic Party received 24.41 percent of the votes (a slight reduction from the 2004 election in which the party received 24.56 percent). The result was the lowest for the Social Democratic Party since the introduction of universal suffrage in Sweden in 1921. In a speech before trade unionists during the election campaign on 12 May 2009, Sahlin said: "If there's not a plus in front of our figures it's a deep failure". On the 19th of September 2010 her bid to become Swedish prime minister failed and SAP received the lowest recorded percentage of the votes in their long history but still is the largest party in Sweden by a slim margin.

In October 1995 the newspaper Expressen revealed that Sahlin, who was then serving as Deputy Prime Minister and was widely seen as the main candidate to succeed Ingvar Carlsson as Prime Minister, had charged more than 50,000 Swedish kronor for private expenses on her working charge card, which was only for working expenses. Sahlin decided to take the case to court to prove her innocence and be cleared of all accusations of misconduct. The criminal charges against her were eventually dropped. The controversy was dubbed as the "Toblerone affair". In 1996 Sahlin's autobiography Med mina ord ("With My Words") was published. The book dealt mostly with the Toblerone affair.

Mona Sahlin has one brother and two sisters. Her brother, Janne "Japop" Andersson, used to be the lead singer of the pop group Japop and owns his own production company. Her sister Lena (Ridemar) is director of negotiation at the Swedish Union of Tenants (Swedish: Hyresgästföreningen) and her other sister works at SEB (Skandinaviska Enskilda Banken).

In 1976 Sahlin met the Chilean David Peña at a Social Democrat youth camp in Kramfors. Their daughter Ann - Sofie was born in 1978, but the relationship only lasted for a few years. In 1982 she married her current husband Bo Sahlin, with whom she has had three children: Jenny (born 1983), Gustav (born 1989), and Johan who died after ten months as a result of heart failure. Sahlin has talked openly about the death of her son Johan.