Henri-Mamert-Onésime Delafond (13 February 1805 – 15 November 1861) was a French veterinarian born in Saint-Amand-en-Puisaye, Nièvre department.

Delafond was one of the primary representatives of veterinary science in France during the first half of the nineteenth century.

[1] Delafond is remembered for pioneer microscopic research of Bacillus anthracis, the causative organism of anthrax.

Also, with microbiologist David Gruby (1810–1898), he performed extensive investigations of Tritrichomonas suis, a parasite found in swine.

In 1842 with Gabriel Andral (1797–1876) and Jules Gavarret (1809–1890), he was co-author of an important treatise on domestic animal blood composition titled Recherches sur la composition du sang de quelques animaux domestiques, dans l’état de santé et de maladie.