The Territorial Abbacy of Santa Maria of Grottaferrata is an ecclesiastical jurisdiction which administers the Byzantine Rite Abbey of Saint Mary in Grottaferrata located in Grottaferrata, Rome, Lazio, Italy.
The Abbacy and its territory are stauropegic, that is, directly subordinate to a primate or synod, rather than to a local bishop. It is the only remnant Eastern Christian monasticism of Byzantine tradition in Italy, further brought to the monastery by the Italo-Albanians, the only ones to historically preserve the Byzantine rite on the peninsula. It is also the only monastery of the Italian Basilian Order of Grottaferrata, (abbreviated O.S.B.I.), a religious order of the Italo-Albanian Greek Catholic Church. The abbot ordinary is also the superior general of the Italian Basilian Order of Grottaferrata. Though normally led by an abbot, the Abbacy has been under the authority of Bishop (now Cardinal) Marcello Semeraro since Pope Francis named him Apostolic Administrator of the Abbacy on 4 November 2013.