Wiener Kammeroper, Opera house and theatre at Fleischmarkt Street, Vienna, Austria.

The Wiener Kammeroper performs in the former ballroom of the Hotel Post at Fleischmarkt 24, converted into an opera stage in 1961. The house opened with short operas by Martinů, Orlandini and Monteverdi as adapted by Carl Orff. It seats a small audience, so the stage and singers stay close to the spectators.

Hans Gabor founded the ensemble in 1948 as the Vienna Opera Studio, performing without a fixed venue at the Konzerthaus and Schönbrunn Palace. It took the name Wiener Kammeroper in 1953. A 1961 subsidy from the Ministry of Education and the City of Vienna let it convert the former ballroom of the Hotel Post on Fleischmarkt into a permanent stage, inaugurated with short operas by Martinů, Orlandini and Monteverdi.

The house gave early stage work to singers and directors who later became known internationally, and from 1982 to 2012 it ran the International Hans Gabor Belvedere Singing Competition, with auditions in around 50 cities. Since 2022/23 the MusikTheater an der Wien's CAMPUS programme brings students from European academies onto the Fleischmarkt stage alongside established singers.

The historic building in central Vienna is easy to reach on foot, but accessibility is limited due to its architectural design. Visitors should plan ahead as the space has stairs and level changes that make wheelchair access impossible.

The theatre's 1986 production of Leoncavallo's Pagliacci, staged by George Tabori, was invited to the Berlin TheaterTreffen and recorded for television. Earlier, from 1992, Mozart operas were performed open-air at the Roman Ruin in Schönbrunn Palace gardens until conservation concerns ended the series in 1999.