The only child of the Danish noble Hartvig Andersen Huitfeldt till Skjelbred och Rommegaard (d. 1637), who lived in Norway, and the Norwegian noble Bente Jonsdotter Schack (d. 1622). Married to Danish noble Tomas Iverssön Dyre till Hvidstedgaard (1605–1651) in 1635. She had three children, who all died very young.
Margareta became one of the greatest land owners in Scandinavia as the heir of her parents and her spouse. She resided in Bohuslän, were most of her properties were situated. Bohuslän belonged to Norway (and thereby Denmark), but became Swedish in 1658. She was a local power holder, with good and influential connections to the authorities. She wished for better conditions for the peasants.
Margareta Huitfeldt is frequently portrayed in the local legends of Bohuslän. During the famous witch trials of 1668–76, the fact that she disliked one of the alleged witches, Helga i Pilanna, who was one of the most well known victims of the Swedish witch hunt, is considered to have led to the condemnation and execution of Helga (1672).
In 1664, she made a famous donation; paid schooling for 30 students a year in Gothenburg, scholarships and support to science. Her will and donation was put under the protection of the crown. It was named "Kungl. och Hvitfeldtskastipendieinrättningen" (1694). This donation has been known as Hvitfeldtska gymnasiet.
- Göteborgs donatorer - från äldre tid intill våra dagar, första delen, Hugo Fröding 1911
- Bohusläns historia, prof. Erik Lönnroth 1963 s.214-215
- Hvitfeldtska Gymnasiet
- Bohusläns Adel, A 318 J A Nordströms arkiv vid Göteborgs Landsarkiv 1938
- Margareta Huitfeldt, Beata Losman 1984
- Sundsby - hus med historia, Eibert Ernby/Bohusläns museum 1988
- Hvar 8 Dag : illustreradt magasin, Sjette årgången, [2 oktober 1904 - 24 September 1905], Förlags AB Hvar 8 dags tryckeri, Göteborg 1905. Avsnitt: "Fru Margrete Huitfeldt", av riksarkivarie H. J. Huitfeldt-Kaas, s. 222-223
- Ruth Larsson - En trollkona skall du icke låta leva.