Heide Simonis (German: [ˈhaɪdə ziˈmoːnɪs]; 4 July 1943 – 12 July 2023) was a German author and politician of the Social Democratic Party (SPD). She was minister of finance in Schleswig-Holstein from 1988 until 1993, when she became minister-president of Schleswig-Holstein. She was the first woman to serve as head of a state government in German history and the only woman to do so in the 20th century, serving until 2005. As of September 2023, she is also the longest serving former female minister-president of a German state (11 years, 343 days).

Born Heide Steinhardt in Bonn on 4 July 1943,^[1] she was the oldest of three sisters.^[2] She had asthma as a young child and therefore spent time in children's homes from age three.^[3] She completed school with the Abitur in 1962 in Nürnberg.^[1] She then studied economics and sociology at the universities of Erlangen-Nürnberg and Kiel, graduating with a degree in economics in 1967.^[1][4] She worked in different positions after 1967, beginning as a lecturer at the University of Lusaka in Zambia.^[1] She worked with her husband for an advisory panel of the WHO in Japan on health development.^[5] She later worked as vocational counsellor at the employment office of Kiel.^[2]

In 1967, Simonis married Udo E. Simonis [de] who had studied with her.^[2][4] He became a professor of economics, with a focus on the environment.^[4] Among her hobbies was quiltmaking.^[5]

Simonis survived breast cancer.^[5] She announced in 2014 that she was diagnosed with Parkinson's disease.^[4] She died at home in Kiel on 12 July 2023, at age 80.^[2][10]

President Frank-Walter Steinmeier described her as an exceptional political personality who shaped democracy beyond Schleswig-Holstein. He noted her competence, but also humanity and empathy.^[11]

Books by Simonis include:^[3]

• Simonis, Heide (1997). Kein Blatt vorm Mund (in German). Hoffmann Und Campe Verlag. ISBN 3-455-11192-0.
• —— (2003). Unter Männern (in German). C.H.Beck. ISBN 3-406-50959-2.
• ——; Maletzke, Erich (2007). Ausgeteilt, eingesteckt (in German). Zu Klampen!. ISBN 978-3-86674-012-9.
• ——; Steinhardt, Dodo; Steinhardt-Böttcher, Barbara (2008). Drei Rheintöchter (in German). Bouvier. ISBN 978-3-416-03234-6.
• —— (2010). Verzockt! (in German). Vandenhoeck & Ruprecht. ISBN 978-3-525-30002-2.
• —— (3 July 2013). Alles Märchen! (in German). ISBN 978-3-7859-1126-6.
• —— (2016). Heringstage (in German). Borbyer Werkstatt Verlag. ISBN 978-3-940586-10-0.

• 2014 – Honorary citizen of Schleswig-Holstein^[4][10][12]
• 2018 – Willy Brandt Medal [de]^[2][4]