Stadtpfarrkirche , situated in Herrengasse, is the oldest parish church in Graz, first mentioned in historical records in 1343. The church was originally a small Gothic chapel; Baroque elements were added later. Today's church is mainly Neogothic in style, the only remaining Baroque elements being the chapel of St. John Nepomuk and the "Assumption of Mary" above the High Altar. The tower of Stadtpfarrkirche rises above all other buildings in the street. The church organ is among the finest in Austria.

Katharinenkirche (St. Catherine's Church), together with the Mausoleum, form a beautiful architectural ensemble. The church was designed by architect Giovanni Pietro de Pomis in 1614. The Katharinenkirche building is one of the most important mannerist buildings in Austria.

Stiegenkirche (Church of the Stairs) is a Roman Catholic church situated in Sporgasse. The church is located in the oldest part of Graz and was originally the monastery church of the Augustinian Hermits. It was rebuilt between 1613 and 1628, but the original staircase, which now gives the church its name, was preserved.

Franziskanerkirche (Franciscan Church), located in Franziskanerplatz, is considered to be one of the oldest churches in Graz. The church and monastery were begun around 1239 and were finally completed around 1277. The Franziskanerkirche bell, dating to 1272, is also one of the oldest bells in city. On entering Franziskanerkirche, the visitors are impressed by the harmonious combination of Gothic architecture and 20th century works of art.

Altkatholische Kirche, located in Kernstockgasse, is a splendid Catholic church, dedicated to Saint Christopher. An orphanage with its associated church occupied this location in the 17th century. The building was later converted into school and then, in 1901, into the present church. Inside the church there is a beautiful Christmas creche in the form of a winged altar.

Mariahilferkirche (Church of Our Lady of Succor), located in Mariahilferplatz, dates back to the 17th century and was designed by Giovanni Pietro de Pomis in the Baroque style. The twin towers of the church were constructed in 1742. The interior of the church is simple but beautiful.

Dreifaltigkeitskirche (Holy Trinity Church) is a Roman Catholic church, which is located between Schlossbergplatz and Murkai in Sackstrasse. The church was built in the Italian Baroque style between 1694 and 1704. Adjoining the church are a monastery and school. The church is located just a few minutes walk from the Murinsel.

Antoniuskirche, situated next to Universalmuseum Joanneum, is a Roman Catholic church, built in 1600 and dedicated to St. Anthony of Padua. The church contains a beautifully ornamented Baroque altar. The altarpiece was painted by the famous artist Giovanni Pietro de Pomis, the architect of the Mausoleum and St. Catherine's Church.