The Württemberg Mausoleum is a memorial in the Rotenberg part of Untertürkheim in Stuttgart, Germany. The mausoleum stands on the peak of Württemberg Hill at the westernmost end of Schurwald woods overlooking the Neckar river. The memorial was built for Catherine Pavlovna of Russia (1788–1819), the second wife of William I of Württemberg (1781–1864). The remains of William I and his daughter Maria Friederike Charlotte of Württemberg (1816–1887) are also housed in the mausoleum.
The mausoleum was built after the death of Queen Catherine between 1820 and 1824 based on a design drafted by Giovanni Salucci. The location on the former site of Fort Wirtemberg was chosen as the home of the House of Württemberg.
Between 1825 and 1899 the mausoleum was used as a Russian Orthodox Church place of worship. The memorial is still used to this day for a Russian Orthodox service every Pentecost.
The mausoleum is inspired by the Villa Capra "La Rotonda" build by Andrea Palladio. The building stands by itself in the middle of the vineyards along the river Neckar making it visible from afar.