In 1297 the first church was built in Marktl and consecrated to St. Oswald. In 1701, triggered by a lightning strike, a large fire broke out in which the church and much of Marktl were destroyed.
After the reconstruction it was soon discovered that the church was too small for the growing population. Hence, 150 years later a new building was erected, which was consecrated in 1875.
In 1965, during the tenure of Father Karl Dussl, the church was enlarged with a modern extension. Only the choir room with the neo-Gothic altar remains.