Saint John Đoạn Trinh Hoan was born in 1798 in a village belonging to the Kim Long family line, Phú Xuân, Diocese of Huế. His parents were virtuous laypeople who lived by weaving silk.

From a young age, young Hoan showed intelligence and a love for learning. His uncle, Father Kiệt, took him as a student, raising him, teaching him, and instructing him in Latin. Afterwards, he was sent to study at the Penang Seminary. After completing his studies, Master John returned to the country, assisting Bishop Taberd – Từ with the work of translating religious books and documents. In 1836, he was ordained a priest by Bishop Etienne Cuenot – Thể in Sài Gòn.

Throughout his 26 years as a priest, Father John Hoan always humbly accepted assignments according to his superiors' will. He was zealous in his activities yet remained calm, prudent, and loved everyone wholeheartedly.

On the evening of January 3, 1861, government soldiers ambushed and arrested Father Hoan. At that time, he was hiding in a haystack. The official ordered a layperson to be seized and beaten, tortured to reveal the religious leader's whereabouts. Witnessing this inhumane torture, unable to bear letting another suffer in his place, Father Hoan stepped out from the haystack and surrendered himself. The soldiers cheered triumphantly, tied up the two fathers (the priest and the layperson) along with a few church dignitaries, took them to the Đồng Hới courthouse, and imprisoned them in a dark cell. At this time, he was 63 years old.

In prison, Father Hoan was tortured many times, forced to step over a crucifix, and forced to reveal the hiding places of the Bishop and the missionaries. Yet he always maintained a merciful attitude in his words. This compassionate demeanor, following the example of Christ, stirred the compassion of the guards. As a result, they did not forbid the visits, the bringing of the Blessed Sacrament, and the provision of essentials by the nuns and laypeople.

When the faithful came to bid him farewell, Father Hoan used the words of Saint Paul, the Apostle to the Gentiles, to exhort them: "Brothers and sisters, follow my example, as I follow Christ; live in His peace and pray for me."

At dawn on May 26, 1861, under the reign of King Tự Đức, he was escorted to the execution ground with this sentencing order: "The criminal named Hoan, occupation religious leader, spreading false doctrine among the people, is sentenced to be beheaded."

Priest John Đoạn Trinh Hoan was beatified on May 2, 1909, and was canonized as a saint on June 19, 1988.