Xavier de Mérode (Frédéric François Xavier Ghislain; Brussels, 1820 – Rome, 1874) was a Belgian prelate, archbishop and statesman of the Papal states.
The son of Count Félix de Mérode-Westerloo who held successively the portfolios of foreign affairs, war, and finances under Leopold I of Belgium, and of Rosalie de Grammont, he was allied through the House of Mérode to the aristocracy of France. Losing his mother at the age of three, Xavier was brought up at Villersexel, in Franche-Comté, by his aunt Philippine de Grammont, second wife of his father.
He attended for a time the Jesuit High School of Namur, then entered the Collège de Juilly presided over by de Salinis, whence he passed (1839) to the Military Academy of Brussels. Graduating with the rank of second lieutenant, after a short service at the armoury of Liège, he joined (1844) as foreign attaché the staff of Maréchal Bugeaud in Algeria, winning the cross of the Légion d'honneur.
In 1847, he abruptly resigned the military career and went to study for the priesthood at the Gregorian University, in Rome, where he was ordained (1849). There he became friend with Count de Woelmont. Assigned, after his ordination, as chaplain to the French garrison of Viterbo, he was being pressed by his family to return to Belgium when Pope Pius IX, with a view to attach him permanently to his court, made him cameriere segreto (1850), an office which entailed the direction of the Roman prisons. The work done by Mérode for the penitentiary system in Rome is described by Lefebvre and Maguire;de Rayneval, the French envoy at Rome, praised it in an official report to his government;Gioacchino Pecci, Archbishop of Perugia, wanted the young cameriere to inaugurate similar work in his metropolis.