[1] In 1881 he wrote a thesis De la ponctuation and graduated from the École Nationale des Chartes.

At the same time, he undertook research on ancient libraries and the history of printing and books.

[1] Between 1900 and 1921, Omont was president of the Société libre d'agriculture, sciences, arts et belles-lettres de l'Eure.

from the University of Oxford in October 1902, in connection with the tercentenary of the Bodleian Library.

[2] After his death, his private library stayed with his widow until it was bought in 1948 by the Catholic University of Leuven, to help reconstruct its collections after they were destroyed by the Germans for the second time.