She was formerly one of three party spokespersons from 2013 to 2015, and became leader in 2015 by displacing the party's founder Bernd Lucke after an internal power struggle; Lucke subsequently left the party and said it has "fallen irretrievably into the wrong hands" after Petry's election. Petry is noted for her anti-Muslim views and for her calls to ban minarets, and for arguing that German police should "use firearms if necessary" to prevent illegal border-crossings. She is a chemist by education and has a professional background as a small businesswoman.
In April 2017, Petry stepped down as AfD's candidate for chancellor due to reports that she wanted to change the party's policies to appeal to more moderate voters. This came after she had frequently criticised the party's right wing representative, Björn Höcke, who had called the Holocaust Memorial in Berlin a "monument of shame", and backed attempts to expel him, but couldn't prevail in a power struggle with her party rivals Jörg Meuthen and Alexander Gauland, who accused her of splitting party ranks. Despite the internal strife, her party voted to allow her to run for a seat in the German parliament in the September 2017 elections.
Petry was born in Dresden, and grew up in Schwarzheide in Brandenburg near Saxony up to 1989. In 1992 her family moved to Bergkamen in Westphalia. Petry took her first degree in chemistry at the University of Reading in 1998, before attending the University of Göttingen, gaining a doctoral degree there in 2004.
Petry is described as a representative of the national conservative wing of her party by political scientists like Lars Geiges, Stine Marg, Franz Walter, Gudrun Hentges, Jürgen W. Falter and Frank Decker. To the contrary, political scientist Cas Mudde describes her as a representative of the far-right wing of her party. Petry describes herself as national-conservative and supporting policies of "national self-determinism." Der Spiegel reports that her electoral success on 4 July 2015, which gave her the reins of leadership in the AfD in preference to Bernd Lucke, the founder, was made possible by the national-conservative wing of the party. Bernd Lucke's wing did not have the majority.
On the subject of the political spectrum, Petry has said, "Right and left are terms that haven't fitted for a long time." Petry believes sharia is incompatible with the "democratic and liberal order of state" and has said that the majority within her AfD favors a liberal-conservative policy.
In January 2016, when a reporter from the regional newspaper Mannheimer Morgen asked her about European and German border policies, Petry answered that the German Border police must do their jobs by "hindering illegal entry of refugees." She then falsely invoked German law in order to conclude that the border police may "use firearms if necessary" to "prevent illegal border crossings", a statement which contradicts the Convention Relating to the Status of Refugees. The reporter followed up on her response, using the term Schiessbefehl which means "order to shoot". Petry stated that she did not use that term, going on to state that no policeman "wants to fire on a refugee and I don't want that either" but that border police must follow the law to maintain the integrity of European borders. Afterwards, Petry made several attempts to justify these statements.
She has recently been criticized by Lutz Bachmann of the anti-Islamic movement Pegida for supporting the right of Muslim Germans to circumcision. In a rough draft of its manifesto, the AfD had considered adopting a stance stating that male circumcision should be outlawed, but Petry said in her interview with Tim Sebastian on 21 March 2016 that this language would not be in the final draft. The Central Council of Jews in Germany is also in an uproar over the question of religious circumcision, stating that to give precedence to a child's self-determination over his parents' right of freedom of religion is "an unprecedented and dramatic intrusion on the right to self-determination of religious communities." This national dialogue is happening in the wake of a 2012 decision of a Higher Regional Court in Cologne, which called the circumcision of a 4-year-old boy "bodily harm." Bachmann is of the view that a man should be 18 before being able to decide whether or not he wants to be circumcised. He has also said that Petry is "scared of Germany's past with Jewish people."
Unlike the CDU and SPD, Petry does not believe mandatory quotas are the right way to give opportunities to women, nor does she believe they improve the chances of women having more leadership positions. She believes quotas make women unsure of whether a promotion would be made on the basis of qualifications.
Regarding the issue of burqas, Petry believes it shouldn't be compulsory for women to dress in such a manner. She has said that in schools "this sort of religious costume should not be worn."
On the issue of international migration, Petry is of the view that, "We [Germany and the rest of Europe] have to decide what sort of migration we want to accept." She has said, "Deciding about who's migrating and who's not, who's going to be part of a new country is, in the end, a question of borders, whether you see them, or whether you don't. When I go to France, I don't see the border, but I know it's there and I accept it, be it in terms of speed limits, or be it in terms of laws and legislation."
In 2007 Petry founded her own business, PURinvent, a Leipzig-based manufacturer of polyurethane tire fill products. She received the Medal of the Order of Merit in 2012.
As noted by the news magazine Stern, she speaks fluent English.
Petry separated from her husband Sven, a Lutheran pastor, in October 2015. Her domestic partner is Marcus Pretzell. She has four children and lives in Tautenhain, Saxony. Petry published a statement in early October 2015 in which she announced that she would separate from her husband, while also noting that "much more than just friendly feelings" had developed between her and fellow party member Marcus Pretzell. Sven has since joined the CDU.
Petry is a member of the Evangelical-Lutheran Church of Saxony, a member church of the Evangelical Church in Germany (EKD). She criticizes many stances of the EKD, which historically holds a largely liberal Protestant stance, claiming it follows "only its own interests" regarding immigration. She advocates its cooperation with AfD in order to defend the European Christian values of the West.