Frogner Manor (Frogner Hovedgård) was a manor house and former estate in today's borough of Frogner in Oslo, Norway. The estate comprised most of the modern borough of Frogner, which has been named after the estate, and Frognerseteren with parts of the Nordmarka forest (Frognerseterskogen). The remaining part of the estate is now the site of the Frogner Park, with the manor house found in the south of the park and the Vigeland Sculpture Arrangement in the park's centre. The 18th century buildings on the grounds are now occupied by the Oslo Museum.
Frogner was one of the largest and oldest agricultural properties in the Oslo area. In the Middle Ages, Frogner became ecclesiastical property, mostly owned by the Hovedøya Abbey, but was confiscated by the Crown in 1532, preceding the Reformation. From the mid 17th century to the late 19th century, it was owned by wealthy officials or burghers of Christiania, but it was sold to the municipality of Kristiania in 1896 to make room for urban expansion and a new cemetery (Vestre gravlund). However, significant parts of the estate instead became a public park.
Frogner Manor was built in 1750 by Major Hans Jacob Scheel (1714-1774), the first owner to make Frogner his permanent residence. In 1790 the estate was bought by timber merchant and shipowner Bernt Anker (1746–1805), Norway's richest person at the time. He extended the main building to its present size. He died a childless widower in 1805, and Frogner was bought by his nephew Morten Anker in 1807. His business was hard hit by the economic depression during and after the Napoleonic wars, and he eventually went bankrupt and was forced to sell Frogner by auction in 1836. The buyer was the director-general of the Modum Blue Colour Works, Benjamin Wegner, who was married to Henriette Seyler of the Hamburg Berenberg banking dynasty.