The former Roman Catholic Diocese of Wiener Neustadt in Lower Austria existed from 1469 to 1785. In 1990, it was re-established as a titular see which is held by the bishop for the Military Services in Austria.
Upon the request of the Emperor Frederick III, it was erected by Pope Paul II on 14 January 1469, and was immediately subject to the Holy See. At first it was coterminous with the town of Wiener Neustadt.
In 1769 the new parish of Theresienfeld was added and in 1784 its territory was extended from Wiener-Neustadt to the boundary of Styria. On 21 April 1785, the see was incorporated in the Archdiocese of Vienna by Emperor Joseph II. Its last bishop, Johann Heinrich von Kerens, S.J. (1775–1785), and his cathedral chapter were transferred to the newly erected Diocese of Sankt Pölten.
The Late-Romanesque Dom or Cathedral was consecrated in 1279AD and remained the cathedral from 1469 to 1785. The choir stalls and transept, in Gothic style, are from the 14th century. In the late 15th century 12 statues of the Apostles were added in the apse, while the bust of Cardinal Melchior Klesl is attributed to Gian Lorenzo Bernini.