Johann Anton Weinmann (Russian: Иван Андреевич Вейнман; 23 December 1782, Würzburg - 5 August 1858, Pavlovsk) was a German botanist who served as Inspector of the Gardens in Saint Petersburg, Russia. He published a Flora that is the basis of some binomial species identifications.
Beginning in 1803, he was head gardener of the newly established botanical garden in Dorpat; from 1823 he served as inspector of the garden of Empress Maria Fyodorovna in Pavlovsk near St. Petersburg.
He also studied fungi (being, for instance, the original author for the name Echinoderma acutesquamosum) and his name is commemorated with the mycological genera Weinmannioscyphus and Weinmannodora, the latter genus being circumscribed by Elias Magnus Fries in 1849.