Monika Mann (7 June 1910 – 17 March 1992) was a German author and feature writer. She was born in Munich, Germany, the fourth of six children of the Nobel Prize–winning author Thomas Mann and Katia, née Katharina Pringsheim.
She trained as a pianist and her early attempts at a musical career seemed promising, but were not met with success and she instead pursued a career as a writer. She married in 1939 but lost her husband the following year, when the ship on which they were travelling to Canada was sunk by a German submarine. Later that year she joined her family in Princeton, New Jersey, and was granted US citizenship in 1952.
Between 1954 and 1986, she lived with her partner Antonio Spadaro in Villa Monacone on Capri. This was her most productive time as a writer and her books and several magazine articles were written during this period. After the death of her partner she left Capri and spent her last years until her death with her brother Golo's adopted family in Leverkusen, Germany.
Thomas Mann was already well established as a novelist and short story writer at the time of Monika's birth, although his Nobel Prize came many years later. Her mother, born Katharina Hedwig Pringsheim, was the daughter of the German Jewish mathematician and artist Alfred Pringsheim and the actress Hedwig Pringsheim.
Monika had an elder sister, Erika (1905–1969) and two elder brothers, Klaus (1906–1949) and "Golo" (1909–1994). A year after Monika's birth her mother was ill with a lung complaint and was one of the first patients to be admitted to the Wald Sanatorium in Davos, Switzerland. There was an interval of eight years before the birth of the last two children, a sister Elisabeth (1918–2002) and a brother Michael (1919–1977). Her uncle was the novelist Heinrich Mann.