Leonidas Iasonidis (1884–1959) was a Pontic Greek political activist born in Bulancak in Pontus, Turkey.
He played a vital role in having the icon of the Virgin Mary (Panagia Soumela) returned to its rightful owners in Greece.
During World War I, he left Paris via Romania and arrived in Rostov, Russia, where he came in contact with the Greek communities of the Caucasus.
In 1917, the Caucasus and Crimean regions were heavily populated with Pontic Greek refugees who had earlier fled Turkey to avoid the Turkish massacres.
These efforts resulted in the Turkish government calling for his arrest, but they were unable to capture him.