Born in Lucerne, she was the daughter of Béla Sekula (1881-1966) an Hungarian who went to Switzerland at 1913 and married Berta (Bertie) Huguenin (1896-1980) at 9th October 1916. She attended a private school Brun in Lucerne, then a private school in Zuoz, and the "Handlesschule" in Lucerne. She then studied at the "Hochalpine Töchterninstitute" in Ftan.

Between 1934 and 1935 she studied language, art and painting studies in Hungary and in Florence, Italy. Sonja Sekula moved with her parents to the U.S.A. in 1936. After attending George Grosz's private art school on Long Island, she enrolled at the Art Students League, where she studied with Morris Kantor and Raphael Soyer.

But her mature style is based on Klee and the work of Matta, Duchamp and Ernst, artists who often appeared at her parents' Park Avenue salon in the late '30s and early '40s. She also enjoyed a close association with Andre Breton, and her chronic bouts with mental illness may have been partly redeemed for her by Surrealism's valorization of the irrational.

In 1945, she fell in love with the paintres Alice Rahon (the wife of Wolfgang Paalen). In Spring 1949, she went to Europe (with an American passport) and lived for two years in Paris. She spent the Summer in St.Tropez, where she met Thoeren with whom she was very much in love. In September she visited Capri with Natica Waterbury proceding to Rome and Athens.

In 1951, after the opening of her third exhibition at the Betty Parsons Gallery, she suffered a breakdown. Taken to the psychiatric clinic of the New York hospital in White Plains, she leaved the hospital towards the end of the year and moves to back to her parents on Park Avenue.

In the following years she was often in and out of several psychiatric clinics, suffering from severe depressions.

Sekula, openly lesbian, hangs herself in her studio in Switzerland, in the wake of a depression brought on by a failed love affair with another woman and perhaps also by the neglect into which her work had fallen.

She is buried in St.Moritz as she had requested in a letter to her mother.