The logothetēs tōn oikeiakōn (Greek: λογοθέτης τῶν οἰκειακῶν), originally the epi tōn oikeiakōn (ὁ ἐπὶ τῶν οἰκειακῶν) was a Byzantine official with varying duties.
The oikeiakoi (from οἰκειακός, "belonging to the household") were a class of senior imperial household officials attested in the 9th and 10th centuries. The position of a head of this class (epi tōn oikeiakōn means "in charge of the oikeiakoi") appeared possibly in the 10th century, based on sigillographic evidence, or at any rate before circa 1030.[1] His exact functions are unclear: Rodolphe Guilland considered him the successor of the epi tou eidikou as the head of the imperial private treasury,[2] while Nicolas Oikonomides thought that he administered the Byzantine emperor's private domains. The post was often combined with other positions, and fulfilled a range of judicial and fiscal duties. In the Palaiologan period, it became the logothetēs tōn oikeiakōn, who exercised mainly diplomatic and judicial duties.[1] According to the Book of Offices of pseudo-Kodinos, compiled around the middle of the 14th century, the logothetēs tōn oikeiakōn occupied the 39th place in the imperial hierarchy, between the praitōr tou dēmou and the megas logariastēs,[3] but held no official function.[4] His court uniform consisted of a turban (phakeōlis) and an overcoat called epilourikon.[5]