Sigrid Maria Schauman was born on 24 December 1877 at Tsuguyev, in the Kharkov Governorate of the Russian Empire (present-day Ukraine), the daughter of general Fredrik Waldemar Schauman and Elin Maria Schauman. Her mother was the daughter of the bishop of Porvoo, Finland. After spending her childhood with her family in Radom, Poland, Schauman came to Finland when she was eight years old. In 1899 she began her studies in the Finnish Association of Arts Drawing School in Helsinki, where her teachers included Carl Jahn and Helene Schjerfbeck. In 1901 she participated for the first time in a group exhibition at the Ateneum.
In 1904 Schauman's brother, Eugen Schauman, murdered the Governor-General of Finland Nikolai Bobrikov. After this she moved to Copenhagen, Denmark, and continued studying in Florence and in Paris,where she was at the Academie de la Palette in 1910 before travelling in Egypt.
She married Edvard Wolff, but her husband died shortly after the birth of their child in 1913.
In 1920 Schauman started work in the newspaper Dagens Press (from 1922 Svenska Pressen, from 1945 Nya Pressen) as an art critic, and worked for the newspaper for almost 30 years, publishing over 1500 art reviews, interviews and travel reports.
In 1939 she visited Rome and Paris.
After World War II, Schauman worked as a teacher in the Free School of Arts from 1945 to 1946. She retired in 1949, but continued painting on a grant provided by the City of Helsinki and an artist's pension from the State of Finland.
During the 1950s Schauman frequently travelled in France and Italy. She was a founding member of the Prisma group of artists in 1956.
Schauman's weakening eyesight prevented her from continuing to paint in the late 1960s. Even a year before her death, Schauman participated in a retrospective exhibition held in honour of her 100th birthday in the Amos Anderson Art Museum. In the same year, she was awarded the Prince Eugen Medal by the King of Sweden for her artistic contributions.
Sigrid Schauman published a biographical book Veljeni Eugen Schauman (Min bror Eugen) ("My brother Eugen Schauman") in 1965.