Gyldenstjerne, also spelled Gyldenstierne and in Swedish Gyllenstierna (English: Golden Star), is a Danish, Norwegian, and Swedish noble family divided into various branches and ranks. It is one of the oldest noble families in Scandinavia. The family surname appears, in the form of Guildenstern, in William Shakespeare's tragedy The Tragedy of Hamlet, Prince of Denmark (see Rosencrantz and Guildenstern).The surname should not be confused with Gyldensteen ("Golden Stone"), the name of another short-lived Danish noble family, first recorded in 1717 and which became extinct in 1749.
The family has a prominent position in Danish, Norwegian, and Swedish history. It belonged to the higher nobility, and paradoxically, in Sweden it supported the absolute monarchy. The member with the highest standing was the noblewoman Kristina Nilsdotter Gyllenstierna, who as Sten Sture the younger's wife was regent consort of Sweden.
The oldest known man in the family is the knight Lord Nils Eriksson of Ågård in Jutland, who is mentioned in 1314 in relationship to Store Restrup Manor (Store Restrup Herregård) in Aalborg. He was the father of Lord Erik Nilsson of Ågård, who had a son Lord Nils Eriksson of Ågård. With this Nils's sons Knud, Peder, and Erik Nilssøner, the family was divided into three primary branches: Restrup, Ågård, and Demstrup. The family in Denmark became extinct in 1729.
The Danish knight Mogens Henriksen Gyldenstierne († 1569) was from 1527 feudal lord of Akershus. In 1532, he was succeeded at Akershus Fortress by his relative Erik Olufsen Gyldenstierne († 1536). The Danish minister Axel Gyldenstierne (ca. 1542–1603) was Governor-general of Norway during the period 1588–1601.