Located in the city centre St. Stephen’s Cathedral, locally known as Stephansdom, is the mother church of the Roman Catholic Archdiocese of Vienna and the seat of the city’s Archbishop. It is also one of the most important Gothic buildings and one of the most frequently visited tourist attractions in Vienna. With its richly decorated multi coloured tile roof and three tall towers, the magnificent Gothic edifice, representing eight centuries of architectural history, is one of the most culturally significant landmarks and an important heritage site of the city.

However, the current structure of the cathedral, largely initiated by Duke Rudolf IV, stands on the ruins of two earlier churches. Supposedly built on the site of an ancient Roman cemetery, the construction of the original church building commenced around 1137 and was consecrated in 1147. Unfortunately, it was entirely ravaged by a large fire in 1258, leaving very little remaining, except only the stone foundations. A larger replacement Romanesque structure was constructed over the ruins of the old church, reusing the two existing towers, which was consecrated on 23 April 1263. Till today, the anniversary of this second consecration is commemorated each year by a rare ringing of the Pummerin bell for three minutes in the evening.

However, it took more than two hundred years for the building to reach its present shape since its consecration in 1263. King Albert I of Habsburg commissioned a Gothic three-nave choir to be constructed east of the church, wide enough to meet the tips of the old transepts, an area set crosswise to the nave, which was completed by his son, Duke Albert II and was consecrated in 1340. Of the three, the middle nave was largely dedicated to St Stephen and All Saints, while the north and the south nave were dedicated to St Mary and the Apostles or the primary disciples of Jesus.

In 1359, the cornerstone of the Gothic nave with its two aisles was laid by Duke Rudolph IV, son of Albert II, which ultimately encapsulated the totality of the exiting old church. Nevertheless, due to the progress of work on the new cathedral, the edifice of the old church was removed from the old church in 1430.

One of the most prominent features of the Cathedral is the Gothic South Tower, popularly known as Steffl, which was completed in 1433. However, it took 65 years from 1368 to complete the massive and 446 feet (136 m) tall tower, which is the highest point and a dominant feature of the Vienna skyline. It served as the main observation and command post for the defence of the walled city in 1529, during the siege of Vienna and again in 1683, during the Battle of Vienna.

The top of the tower is decorated with the double-eagle imperial emblem with the Habsburg-Lorraine coat of arms on its chest, surmounted by a double-armed apostolic cross. It replaced the earlier crescent and the six-pointed star emblem, which is now housed in the Vienna City Museum. However, although the north tower was originally intended to mirror the south tower and its foundation was laid in 1450, its construction was halted in 1511, as the construction of the cathedral was nearing its end. Ultimately, the unfinished tower, which now stands at 223 feet (68 m), roughly half the height of the south tower, was capped with a makeshift Renaissance spire in 1579. The north tower houses the Pummerin, one of Europe’s largest free-swinging bells, etched with images of the Virgin Mary. It is said that Ludwig van Beethoven discovered his total deafness when he saw that birds flying out of the north tower yet could not hear the sound of the Pummerin ringing.

While the main entrance to the church is named the Giant's Door, the area above it, known as the tympanum, depicts Christ Pantocrator, flanked by two winged angels, each standing at approximately 213 feet (65 m) tall. Another remarkable part of St. Stephen's Cathedral is its 364 feet (111 m) long ornately patterned and richly coloured roof, covered by 230,000 glazed tiles.

The lavishly decorated cathedral is filled with artistic delights, which include a late-Gothic pulpit, a masterpiece in stonework, placed in the nave rather than in the chancel, to allow more people to hear the sermon. It also houses the Maria Pötsch Icon, an icon of St Mary with Jesus depicted in the Byzantine style. Initially, it was installed in the Hungarian Byzantine Catholic shrine Máriapócs, but subsequently shifted to Vienna in 1696 by order of King Leopold I, when the icon was allegedly seen in tears.

St. Stephen’s Cathedral, Vienna, contains 18 altars with more in the various chapels, among which the High Altar and the Wiener Neustadt Altar are most famous. The High Altar, built over seven years from 1641 to 1647 of marble from Poland, Syria and Tyrol, represents the stoning of the church's patron St Stephen. It is framed by figures of patron saints, namely Saints Leopold, Florian, Rochus and Sebastian and surmounted with a statue of St Mary, while Christ waits in heaven for Stephen to ascend from below. The Wiener Neustadt Altar, composed of three sections or triptychs and located at the head of the north nave, was commissioned in 1447 by Emperor Frederick III, whose tomb is located in the opposite direction. The upper section of the altar is four times taller than the lower one and when the lower panels are opened, the Gothic grate of the former reliquary depot above the altar is revealed. While the panels remain closed on weekdays and display only a drab painted scene involving 72 saints, they open on Sundays, displaying gilded wooden figures, depicting the important events in the life of the Virgin Mary.

The cathedral contains several formal chapels, which include St Katherine’s Chapel, located in the base of the south tower; St Barbara’s Chapel, in the base of the north tower; St Eligius Chapel, in the southeast corner; St Bartholomew’s Chapel, located above St Eligius Chapel; the Chapel of the Cross and St Valentine’s Chapel, situated above the Chapel of the Cross. Interestingly, the Chapel of the Cross is the place, where Prince Eugene of Savoy was buried and where Mozart‘s funeral took place on 6 December 1791. It is believed that the beard on the crucified Christ above the altar of the Chapel of the Cross is made of real human hair. The cathedral also contains the tombs of Prince Eugene of Savoy and Holy Roman Emperor Frederick III. Apart from that several famous persons were buried in the church, which includes Elisabeth of Austria, Queen of France, Dutch Golden Age painter Jan van Hoogstraten and former Archbishops of Vienna. In addition to that, the catacombs containing the remains of around 10,000 deceased, arranged in parts in tiers stacked on top of one another, lie beneath the floor of the cathedral. Burials directly in the catacombs continued until 1783, when a new law forbade most burials within the city.

During the final months of World War II, St Stephen’s Cathedral was saved from intentional destruction by the retreating German forces, when Wehrmacht Captain Gerhard Klinkicht disregarded orders from city commandant Dietrich to fire hundred of shells to reduce it to rubble. Although the cathedral was saved for the time being, it was not the end of the threat. On 12 April 1945, rowdy civilian hooligans set fire to the shops in Vienna’s historic centre to protest against the invading Soviet Army. As the blowing wind carried the flames from the fire to the roof of the cathedral, the original Gothic timbered-style roof caved in. Although several invaluable artworks were saved by the protective brick shells constructed around the pulpit, Frederick III's tomb and other treasures, unfortunately, the choir stalls, created by Willhelm Rollinger in 1487, could not be saved. However, reconstruction of the cathedral began immediately after the end of the war and the cathedral was partially reopened on 12 December 1948, before being completely open to the public on 23 April 1952.