Franz Xaver Kraus (18 September 1840 – 28 December 1901) was a German Catholic priest, and ecclesiastical and art historian.
Franz Xaver Kraus was born in Trier in 1840. He completed his studies in the Trier gymnasium, began his theology in 1858-60 in the seminary there, and finished it in 1862-64, having passed in France the time from the autumn of 1860 to the spring of 1862 as tutor in distinguished French families. He was ordained a priest by the suffragan bishop Matthias Eberhard of Trier, 23 March 1864. Even after he became a priest, he continued his studies in theology and philology at the universities of Tübingen, Freiburg — where he had received the degree of Doctor of Philosophy in 1862, and received that of Doctor of Divinity in 1865 — and Bonn.
In the autumn of 1865 he became beneficiary of Pfalzel near Trier, where he developed a zealous literary activity, interrupted by several journeys of the purpose of study to Paris, Belgium, and to Rome in January 1870. In the spring of 1872 he was attached to the faculty of philosophy at the university of Strasburg as professor extraordinary of the history of Christian art, and in the autumn of 1878 he succeeded Johann Alzog as Professor ordinary of Church history at Freiburg. In 1890 he was made grand-ducal privy councillor, and held the office of pro-rector of the university for the period 1890-1. He was also curator of religious antiquities in the Grand Duchy of Baden, and from 1883 a member of the Badern Historical Commission.
He was a man of deep religious feeling and Catholic faith, but, from association with the Liberal Catholics in France, Italy, and Germany, he became imbued with their views on ecclesiastical polity. At the time of the Vatican Council, he entered into close connections with the opposition party, and kept up these relations for some time.
He remained in the Church, but the strife had engendered in his mind a certain bitterness. In many anonymous or pseudonymous articles written for the Liberal press, he gave vent to his dissatisfaction with certain ecclesiastical conditions. The "Kirchenpolitische Briefe" in the "Beilage zur Allgemeinen Zeitung" (1895-9), written under the pseudonym of "Spectator", created a great sensation.