Sager House, Prime Minister's residence in central Stockholm, Sweden.

Sager House is the official residence of Sweden's Prime Minister in central Stockholm. The three-story building with mansard roof displays French Baroque Revival architecture with Rococo details and stands at Strömgatan 18.

The site was first documented in the 17th century, but the present building took shape in 1893 when Robert Sager commissioned substantial renovations. It became the official Prime Minister's residence in 1995.

The name comes from diplomat Robert Sager, who bought the property with his brother Edvard in 1880 and had it rebuilt as a private palace. The Sager family lived here until Vera Sager's death in 1988, after which the state bought the house for 45.5 million kronor. Since 1995 it has served as the prime minister's official residence, and the building is blue-marked by the Stockholm City Museum.

The residence faces the Norrström river at Strömgatan 18, between Rosenbad to the west and the Ministry for Foreign Affairs and the Opera at Gustav Adolfs torg to the east. Riksbron and Norrbro bridges link it across the water to the Riksdag on Helgeandsholmen and the Royal Palace on Stadsholmen. It is a working office and home, not open to visitors; the facade and the star-topped stone wall along the street can be seen from outside.

The house was the last privately occupied palace in central Stockholm; Vera Sager, widow of Robert Sager's son Leo, lived there until her death in 1988. The state then bought it for 45.5 million kronor, partly prompted by security changes after the 1986 murder of Olof Palme. The first prime minister to use it after the 1993–1995 renovation was Göran Persson.