The Christian Social Party (, CS) was a major conservative political party in the Cisleithanian crown lands of Austria-Hungary and in the First Republic of Austria, from 1891 to 1934. The party was also affiliated with Austrian nationalism that sought to keep Catholic Austria out of the state of Germany founded in 1871, that it viewed as Protestant Prussian-dominated, and identified Austrians on the basis of their predominantly Catholic religious identity as opposed to the predominantly Protestant religious identity of the Prussians. It is a predecessor of the contemporary Austrian People's Party.