Chapel of the Assumption of the Virgin Mary at Clementinum, Mannerist chapel in Old Town, Czech Republic

The Chapel of the Assumption of the Virgin Mary at Clementinum, known as the Vlašská Chapel, is a Mannerist chapel built between 1590 and 1600 on an elliptical plan. Its interior gallery forms shallow niches, and it was the first Italian chapel of this oval type north of the Alps. A dome fresco of the Assumption, possibly by Giovanni Pietro Scotti, crowns the space.

An older chapel and oratory served Prague's Italian community here from 1569, drawn by Italian-language sermons at the Clementinum. It was demolished in 1589 and rebuilt from 1590; the new chapel was consecrated in August 1600 by Filippo Spinelli, papal nuncio at the court of Rudolf II. Between 1715 and 1735, during construction of St Clement's Church, Baroque alterations moved the main altar from the east to the west side.

The chapel's name comes from the Italian (Vlašská) community of Prague, for whom it was built; Italians chose this site because the Clementinum Jesuits preached in Italian. In 1942 the Italian Congregation of the Assumption transferred the chapel, together with its chapel and hospital in Vlašská Street in Malá Strana, to the Italian state. The interior paintings, including the dome fresco of the Assumption, date from 1734 and their authors are not reliably known.

The chapel stands on Karlova Street in the Old Town, connected to the Clementinum and sharing an entrance portico with the Church of St. Clement; it lies behind the sanctuary of the Church of Our Lady of the Salvation. The interior was rearranged in 1715–1735, when the main altar moved from the east to the west side and a small balcony was built above the new entrance.

The chapel's elliptical plan with an inner ambulatory of shallow niches is considered the first Italian chapel on an elliptical ground plan north of the Alps. The fresco in the dome, attributed to Giovanni Pietro Scotti, replaced the original Mannerist decoration during the 1715–1735 Baroque remodelling.