Père Jean Marie Delavay (28 December 1834 – 31 December 1895) was a French missionary, explorer and botanist.
He was sent to China in 1867, serving first in Guangdong, then moving to Kunming, Yunnan, where he remained until his death. He was perhaps the first Western explorer of the region which is now encompassed by the Three Parallel Rivers of Yunnan Protected Areas.
He was an avid plant collector, sending over 200,000 herbarium specimens back to France, from which numerous new genera and over 1,500 new species were described, many by Adrien René Franchet of the Paris Muséum national d'Histoire naturelle.
He is commemorated in the names of several plants, including Delavay's Fir Abies delavayi, Delavay's Magnolia Magnolia delavayi and Delavay's Peony Paeonia delavayi.