The papias (Greek: παπίας) was a eunuch official in the Byzantine court, responsible for the security and maintenance of the buildings of the imperial palaces in Constantinople. He commanded an extensive staff and performed in important role in palace ceremonies. In the Palaiologan period, the honorary title of megas papias ("grand papias") was created and awarded to senior aristocrats.
The term is etymologically connected to πάππος or παπᾶς ("father, priest"). It is first attested in a seal dated to circa 550–650, and next recorded in the chronicle of Theophanes the Confessor for the year 780. There were three papiai, all eunuchs: one for the Great Palace itself (παπίας τοῦ μεγάλου παλατίου, papias tou megalou palatiou), and two others for its adjuncts, the Magnaura and the palace of Daphne (the παπίας τῆς Μαγναῦρας and παπίας τῆς Δάφνης). The latter was created by Emperor Michael III (r. 842–867), while the former is attested only in Philotheos's Kletorologion of 899. The papias of the Great Palace was a very important official. Often styled "grand papias" (Greek: μέγας παπίας, megas papias), and usually holding the rank of protospatharios, he was the concierge of the palace and responsible for its security. He held the keys to the doors of the palace (and of the palace prison) and opened them every morning together with the megas hetaireiarches. He thus controlled physical access to the imperial quarters, and was an important element in any conspiracy against the Byzantine emperor's life, as demonstrated in the usurpations of Michael II in 820 and Basil I in 867. It is possible that initially the other two papiai were subordinate to the papias of the Great Palace.