Nahles finished high school (Abitur) through a continuing education program in 1989. She obtained an MA after studying politics, philosophy and German studies at the University of Bonn for 20 semesters (10 years), during which time she was an assistant to a member of parliament. In 2004, she began working towards a doctorate in Germanistics. Nahles abandoned her dissertation in 2005 upon returning to the Bundestag. The title of her planned dissertation was Walter Scotts Einfluss auf die Entwicklung des historischen Romans in Deutschland (Walter Scott's influence on the development of the historical novel in Germany).
In 1988, Nahles joined the SPD. Shortly after, she was the youth representative for the constituency of Mayen-Koblenz. From 1993 to 1995 she was the youth representative for Rheinland-Pfalz. In 1995 she became the national youth representative, following Thomas Westphal, a post she held until 1999. Since 1997 she has been a member of the SPD executive.
In 2000, Nahles was one of the founders of the "Forum Demokratische Linke 21" (Forum of the Democratic Left 21). Further, she is a member of IG Metall, Eurosolar and Attac. As leader of the SPD's left wing and former head of party's youth section, she opposed many of Chancellor Gerhard Schröder's economic reforms, namely the Agenda 2010. She and others repeatedly criticized the leadership style of the party's chairman Franz Müntefering, saying the party was never consulted over Schröder's decision in May 2005 to call early elections or the decision to join a grand coalition under Merkel that would include the major parties.
As party leaders sought to reconcile the bickering factions in the post-Schröder era, Nahles gained in leverage. On 31 October 2005, she was voted the SPD's general secretary, defeating Kajo Wasserhövel, the favoured man from the conservative side of the party. Wasserhövel's defeat prompted Franz Müntefering to declare that he no longer feels he has the confidence of the party and will step down. As a result, Nahles refused to accept the position of general secretary.
Between 2005 and 2009, Nahles served on the Committee on Labour and Social Affairs. From 2008, she was also a member of the SPD parliamentary group’s leadership under chairman Peter Struck.
Ahead of the 2009 elections, German foreign minister Frank-Walter Steinmeier included her in his shadow cabinet of 10 women and eight men for the Social Democrats’ campaign to unseat incumbent Angela Merkel as chancellor. During the campaign, Nahles served as shadow minister for education and integration policies, being a counterweight to incumbent Annette Schavan.
Nahles was elected as the SPD's secretary general in November 2009 at the party congress held in Dresden. She succeeded Hubertus Heil in the position, and worked together with new-elected party chairman Sigmar Gabriel. Her appointment was widely seen as a signal the SPD would shift to the left.
In her capacity as secretary general, Nahles oversaw the SPD’s electoral campaign in 2013. After the SPD's defeat in the federal elections, she was in charge of organizing a referendum among her party's 472,000 members before signing any coalition treaty with re-elected Chancellor Angela Merkel and her conservative bloc. In the negotiations to form a coalition government following the elections, Nahles was part of the 15-member leadership circle chaired by Merkel, Gabriel and Horst Seehofer.
At a three-day party convention held in Leipzig in November 2013, delegates re-elected Nahles to her post with reduced majority. She received 67.2 percent of members’ ballots.
As Federal Minister of Labour and Social Affairs in Chancellor Angela Merkel's third Cabinet, Nahles has overseen the introduction of a national minimum wage for Germany, guaranteeing workers at least 8.50 euros per hour ($11.75). Merkel had campaigned against a statutory minimum wage in 2013, saying it would threaten Germany’s competitive edge and that wage-setting belonged in the hands of companies and employees; however, her party gave ground to the Social Democrats, who made the measure a condition for helping her stay in power for a third term. In early 2015, however, Nahles bowed to pressure from Germany’s eastern neighbours, particularly Poland, and suspended controls by state authorities to check whether foreign truck drivers were being paid the minimum wage.
After having campaigned on the promise of early retirement for longtime workers during the elections, Nahles also managed the introduction of an early retirement law in 2014. The move, which – at expected total costs of about 160 billion euros between 2015 and 2030 – is likely to be the most expensive single measure of the legislative period, was sharply criticized as Germany grapples with an aging population and a shrinking work force and promotes austerity among its European Union neighbors. In late 2014, Nahles also announced that the combined pension contributions from employers and employees would be cut by a total of 2 billion euros in 2015 due to the high level of reserves.
Following annual negotiations between the Claims Conference and the German government in 2014, Nahles successfully introduced a proposal for extending German pension payments totaling 340 million euros ($461 million) for some 40,000 Holocaust survivors who were used by the Nazis in ghettos as laborers in exchange for food or meager wages. Most Holocaust survivors suffered serious malnutrition during World War II and also lost almost all of their relatives, leaving them with many medical problems and little or no family support network to help them cope.
Following a succession of strikes that disrupted Germany's air and train travel in 2014, Nahles introduced a bill which amended labor laws to allow only one trade union to represent employees of one company in negotiating wage agreements, a move critics say in effect will deprive small unions of their right to strike.
In 2015, Nahles commissioned an in-depth study to establish a definition of work-related stress and calculate its economic cost, leading to speculation that the study could pave the way for an "anti-stress act" as proposed by Germany's metalworkers' union.
In response to rightwing populist assaults on chancellor Angela Merkel’s liberal immigration policies, Nahles presented plans in early 2016 to ban EU migrants from most unemployment benefits for five years after their arrival.Central Committee of German Catholics, Member
Denkwerk Demokratie, Member of the Advisory Board
Maria Laach Abbey, Member of the Board of Trustees
Willy Brandt Center Jerusalem, Member of the Board of Trustees
ZDF, Ex-officio Member of the Television Board (2000-2004)
Her partner was from 1997 till 2007 VW manager Horst Neumann. Nahles is married to Marcus Frings and has one daughter. In January 2016 the couple announced its separation.