Katrin Langensiepen was born in 1979 in the Hannover region (Langenhagen). A convinced European, she studied in the Netherlands, was an au pair in the banlieues of Marseille in France, worked on a kibbutz in Isreal and finally trained as a foreign language assistant. In 2011, she was elected to the Hanover City Council for Alliance 90/The Greens, where she was active as social policy spokesperson and campaigned for more participation and solidarity as spokesperson for the Federal Working Group on Disability Policy. At the same time, she worked in the constituency office of Bundestag member Sven-Christian Kindler and in the state parliament office of Filiz Polat and Belit Onay.

In November 2018, she was elected 9th on the European list at the federal party conference of Alliance 90/The Greens and thus entered the European Parliament in July 2019 as the only MEP with a visible disability. At federal level, she has been a member of the newly founded AG-Vielfalt (Working Group on Diversity) since 2019, which promotes the issue of diversity within the Green Party. In the European Parliament, she fights for a social and inclusive Europe as Vice-Chair of the Committee on Employment and Social Affairs.