6/8 Klonowa Street in Warsaw, Protected villa in Śródmieście, Poland.

The Willa Muszyńskiego i Urbanowicza at 6/8 Klonowa Street is a two-family house designed by Bohdan Pniewski and built in 1935–1936. The building is divided into two units with separate entrances, numbered 6 and 8, and has a garden at the rear. Its elevations and fence are clad in sandstone rustication, and a side wall of the porch consists of 25 perforated square plates set into the wall plane. The flat roof holds recreational terraces.

Bohdan Pniewski designed the double house in 1935–1936 for lawyer Stefan Urbanowicz and engineer Leszek Muszyński. After World War II the villa was taken over by the State Treasury, and in 1989 it came under the administration of the Chancellery of the President. During Lech Wałęsa's presidency half of the building, no. 8, was returned to Urbanowicz's heirs; the other half, no. 6, was bought back and later housed Ministry of National Defence offices.

The villa takes its name from its two original owners: lawyer Stefan Urbanowicz and engineer Leszek Muszyński, who commissioned it in 1935. Its two halves, numbered 6 and 8, had separate entrances and later separate fates, with No. 8 returned to Urbanowicz's heirs during Lech Wałęsa's presidency. Today No. 6 houses Ministry of National Defence offices.

The villa is not open to the public: number 6 houses Ministry of National Defence offices, while number 8 is managed by the Stołeczny Zarząd Infrastruktury. Visitors can view the sandstone-clad façade and the garden wall from Klonowa Street. The building stands in Śródmieście, near the intersection with Górnośląska Street.

The side wall of the porch is made of 25 perforated square plates set into the sandstone-clad wall, a detail easy to miss from the street. Inside, the architect used marbles named Dębnik, Barwinek and Racławice, plus an alabaster partition wall.