Pierre Jérôme Honoré Daumet (23 October 1826, Paris – 12 December 1911, Paris) was a French architect.
Daumet was the winner of the Prix de Rome in 1855, and in 1861 conducted a treasure-hunting expedition to Macedonia at the request of Napoleon III, accompanying the archaeologist Léon Heuzey. On his return he married the daughter of architect Charles-Auguste Questel.
Daumet founded his own atelier which would produce nine further Grand Prix winners, Charles-Louis Girault chief among them, and attracted a number of foreign students such as Charles McKim and Austin W. Lord.
Major work includes:
- Extension and western front of the Palais de Justice in Paris, 1857–1868, with Louis Duc
- Reconstruction of the Château de Chantilly, 1875–1882
- Basilique du Sacré-Cœur, Paris, 1884-1886 (Daumet was the first of five successive architects who completed the building after the death of Paul Abadie)
- Grenoble, Palais de Justice, Palais des Facultés