François-Isidore Gagelin (10 May 1799 – 17 October 1833) was a French missionary of the Paris Foreign Missions Society in Vietnam.
He died a martyr, and became the first French martyr of the 19th century in Vietnam.
He was born in Montperreux, Doubs.
He left for Vietnam in 1821.
In 1826, when Emperor Minh M?ng ordered all missionaries to gather at the capital Hu?, he fled to the south to Ð?ng Nai in Cochinchina.
He was captured once and released.
On 6 January 1833, a new edict of prohibition was promulgated by Minh M?ng and immediately put in application.
Churches were destroyed, and missionaries had to live in hiding.
Gagelin surrendered in August 1833, and he was brought to Hu?.
He was killed by strangulation on 17 October 1833, which is the date of his feast.He was beatified in 1900, and canonized in 1988 by Pope John Paul II.