Aigner was born in Feldkirchen-Westerham, Rosenheim, Bavaria and entered Angela Merkel's grand coalition cabinet as Federal Minister of Food, Agriculture and Consumer Protection on 31 October 2008. She succeeded Horst Seehofer who had become minister president of Bavaria. She left her position on 30 September 2013 after being elected as a member of the Bavarian parliament. Since 10 October 2013 she is Deputy Minister-President of Bavaria and Bavarian Minister of Economic Affairs; and Media, Energy and Technology.
Aigner completed a professional training as a telecommunications technician in 1985 and joined the electrical installation business of her parents. In 1990 she graduated from the technical academy with the degree of a State Certified Engineer and worked for several years for Eurocopter in the development of helicopter electric systems.
Aigner was elected first in 1994 to the Bavarian State Parliament.
From 1998 Aigner was a member of the German Bundestag, winning always an absolute majority of the votes in her electoral district.
From 2002 to 2005, she was a member of the Budget Committee, where she served as her parliamentary group's rapporteur on the budgets of the Federal Ministry for Consumer Protection, Food and Agriculture (BMELV) and the aerospace technology portfolio of the Federal Ministry of Education and Research (BMBF). From 2005 to 2008, she served as her parliamentary group’s spokesperson for education and research policy.
Aigner was a little-known member of parliament with no previous ministerial experience when she took over as Federal Minister for Consumer Protection, Food and Agriculture in the cabinet of Chancellor Angela Merkel in 2008, replacing Horst Seehofer.
During her time in office, Aigner steered through a 2011 dioxins scare that saw contaminated eggs and meat from Germany going to six neighbouring countries. In response, she imposed tough new safety standards for animal feed manufacturers, a move widely supported in the market to retain public confidence. She also took a tough line against cultivation of genetically modified organisms (GMOs) in Germany but received praise from commodity traders when she supported imports of GMOs approved in the United States and South America to secure German supplies of soybeans for animal feed. Meanwhile, she repeatedly expressed concern that outside financial investment in agricultural commodity markets distorts prices, instead calling for more transparency in commodity markets and clear visibility of the difference between futures investment by industrial food buyers and financial investors.
In 2009, Aigner caused a controversy when she called for requirements to publish the names and location of recipients of Common Agricultural Policy (CAP) subsidies to be “suspended” until the implications for data protection have been assessed. In response, the European Commissioner for Agriculture and Rural Development Mariann Fischer Boel threatened Germany with legal action.
Aigner has been outspoken in her criticisms of Facebook. She feels that Facebook needs to do more with its settings to protect its users' privacy . For years, she has been fighting for higher privacy standards in Facebook and other social networks. In September 2011, she asked all federal ministers in Germany not to use Facebook for public relations and communication. In 2010, she criticized Google over plans to give property owners a four-week deadline to stop their buildings from showing up on the company’s then newly launched Street View mapping service, demanding that all requests be considered instead.
Amid the German debate on the country’s energy transition to an energy portfolio dominated by renewable energy, Aigner called in later 2012 for the partial nationalization of the country's electrical grid in order to ensure that high-voltage power lines required to transport green energy from offshore windfarms and other sources to the industry-heavy regions of southern Germany are built.
In 2012, Aigner announced she would leave her post to return to local politics in her home state of Bavaria following the 2013 national elections, prompting speculation that she was eyeing the post of Bavarian Minister-President Horst Seehofer.
Following her return to Bavaria after the state's 2013 elections, Aigner was named Minister-President Horst Seehofer's deputy as well as Bavarian Minister for Economic Affairs, Media, Energy and Technology. As one of Bavaria's representatives at the Bundesrat, she serves on the Committee on Cultural Affairs; the Committee on Economic Affairs; and the Committee on the Environment, Nature Protection and Reactor Safety.
In the negotiations to form a grand coalition following the 2013 national elections, Aigner led the CDU/CSU delegation in the working group on economic affairs; her co-chair from the SPD was Hubertus Heil. On 17 December 2013 she became the first woman to ever chair a meeting of the Bavarian State Government.Bavarian Regulatory Authority for Commercial Broadcasting (BLM), Ex-Officio Chairwoman of the Supervisory Board
Federal Network Agency for Electricity, Gas, Telecommunications, Posts and Railway, Ex-Officio Member of the Advisory Board
FilmFernsehFonds Bayern, Ex-Officio Chairwoman of the Supervisory Board
LfA Förderbank Bayern, Ex-Officio Member of the Supervisory Board
Messe München, Ex-Officio Chairwoman of the Supervisory Board
Landwirtschaftliche Rentenbank, Ex-Officio Member of the Supervisory Board (2005-2013)
KfW, Ex-Officio Member of the Supervisory Board (2005-2013)
Bavarian Research Foundation, Ex-Officio Member of the Board of Trustees
Deutsches Museum, Member of the Board of Trustees (since 2004)
Ifo Institute for Economic Research, Member of the Board of Trustees
Max Planck Society, Ex-Officio Member of the Senate
Munich International Film Festival, Ex-Officio Member of the Supervisory Board
Association of the German Army (FKH), Member of the Presidium (2002-2008)
German Energy Agency (DENA), Ex-Officio Member of the Supervisory Board (2005-2011)
Max Planck Institute for Astrophysics, Member of the Board of Trustees (2005-2008)
Max Planck Institute for Extraterrestrial Physics, Member of the Board of Trustees (2005-2008)
Wasserwacht of the Bavarian Red Cross, Chairwoman (2001-2009)
Aigner is a Roman Catholic, a single and has no children.