Guerne was born in Lucerne, Canton of Lucerne, Switzerland on 26 March 1912. She graduated primary and secondary school in Switzerland, where she trained to become a dressmaker. Later, she moved to London, UK, since she needed to learn English, and continued her education at various fashion studios in Paris and St. Moritz. In 1937, she married Henri Guerne. The couple had at least one son: Jean-Pierre.
In 2004, she moved into a nursing home in Orvin. It was reported that she was able to maintain a certain degree of independence until shortly before her death.
Guerne passed away in Orvin, Canton of Bern, Switzerland, on 23 February 2024, at the age of 111 years, 334 days.
On 16 November 2020, following the death of Alice Schaufelberger-Hunzikerhe, she became the oldest known living person in Switzerland.
On 9 March 2021, following the death of Anna Leglise (died in France), she became the oldest living Swiss-born person.
Her age was validated by the ESO on 26 April 2022.
On 13 January 2023, at the age of 110 years, 293 days, she surpassed the final age of Hedwig Hosig-Huggler, becoming the oldest person ever to have lived in the Canton of Bern.
* “Marie Guerne, 105 ans, toujours partante pour une activité” – Résidence Les Roches, April 2007
* “Älteste Schweizerin mit 111 Jahren gestorben” – Blick, 26 February 2024