The Osijek co-cathedral was built by the bishop of the then Diocese of Đakovo and Srijem, Josip Juraj Strossmayer. In 1866, he gave the first impetus for the construction of a new church. At that time, on the site of today's church, there was the Gornjograd parish church from 1732, which became too small and unsightly for the new buildings in Osijek. In 1870, the patron of the parish, the city of Osijek, determined the method of obtaining money for the construction of a new church. However, this process was very slow, until the arrival of the new pastor Josip Horvat. After his arrival, the process was accelerated, so in 1892 a tender for designs was announced. The German architect Franz Langenberg won the competition. In 1894, the old church was demolished, and then the construction of today's co-cathedral began, a magnificent neo-Gothic building with a 94-meter-high tower and three naves. The total area of the church is 1062 m².[2] In 1898, the outside of the church was completed, so the interior decoration continued. Two years later (1900), the present church was consecrated by Bishop Josip Juraj Strossmayer.
The interior was completed between 1938 and 1942, when the leading Croatian painter Mirko Rački covered the walls and ceilings with brightly colored frescoes depicting famous episodes from the Old and New Testaments.
The interior is a veritable treasure trove of neo-Gothic ornamentation, with a succession of superb altars above which are abundant stained glass windows.
The entrance to the church is through a small door located to the right of the main portal, guarded by three fountains.
During the Homeland War, in 1991, the co-cathedral was directly hit by missiles more than 100 times. Nevertheless, religious services were held in the co-cathedral during the war as well. Until June 18, 2008, this co-cathedral was only the parish church of St. Peter and Paul, popularly called the "cathedral" in Osijek, but with the establishment of the Đakovo-Osijek archdiocese, this church gained the dignity of a co-cathedral.