Josef Jakob Halda (born 7 December 1943) is a Czech botanist who worked at the Institute of Botany of the Czechoslovak Socialist Republic.
He studied the flora of the Czech Republic and made a number of expeditions to Mexico.
As a scientist, he studied the taxonomy of genera Paeonia, Daphne and Haworthia.
He also published popular books such as The genus Primula in cultivation and the wild, which was illustrated by his wife Jarmila Haldová.
Later, he collected seeds of primarily alpine plants across Europe and Asia, which he sold to gardeners throughout the world.