Martha Larsson was born in the Scanian countryside, went to a girls' school in Lund, studied in France, and was later employed by the newspaper Svenska Dagbladet in Stockholm. After World War II, she became a correspondent in Rome and moved back to her childhood home, the estate of Sofiedal, much later, in 1980, where she lived together with her sister, the artist Dagny Larsson.
In her debut work, the poetry collection I denna cirkel, 1994, she draws on nature to find the words to describe the Nazi menace. Her collection of short stories I drömmen var det så, 1946, describes how women are punished in their close relationships with others. In Fjärrkontakter (P), 1980, she deals with the subject of violence in everyday life in Italy. Through her feature articles in the newspaper Svenska Dagbladet, Martha Larsson also introduced Italian poets to Swedish readers.