ARCHIDAMO. – A Roman priest of the 4th century. Together with the priest Filosseno and the deacon Leone, he represented Pope Giulio I (337–52) at the Council of Sardica (autumn 343),
at which, together with Filosseno, he apparently assisted Osio in presiding. This would explain why their names immediately follow that of Osio in the list of the fathers present at the Council, handed down to us by St. Atanasio (Apologia contra Ariana, 1), whereas they are absent among the signatories of the probably authentic letter to Pope Giulio, in which the people are told that they will receive further clarification from his legates.
BIBL.: S. Ilario, Fragmenta historica, II: PL. 10, 640; CSEL, 65, p. 127. – Hufelé-Leclercq, I, pp. 748–49, 810; A. Fliche and V. Martin, Storia della Chiesa, Italian translation, III, Turin (1940), no. 128 ff. Ireneo Daniele