Hadoard or Hadoardus was a priest, and presumed librarian (custos librorum), of the ninth century. He is known solely for his Collectaneum, an anthology of philosophical extracts. This is a source, in particular, for the knowledge at the time of the works of Cicero.
- Charles H. Beeson, The Collectaneum of Hadoard, Classical Philology, Vol. 40, No. 4 (Oct., 1945), pp. 201-222
- Charles H. Besson, Lupus of Ferrières and Hadoard, Classical Philology, 43 (1948), 190-91
B. Bischoff, "Hadoard und die Klassikerhss. aus Corbie", Mittelalterliche Studien 1 (Stuttgart 1966) 49-63