Saint Thomas Dinh Viet Du was born in 1783 in Phu Nhai village, Nam Dinh province (now part of Phu Nhai parish, Bui Chu Diocese). He was very diligent in studying and cultivating virtues. After being ordained a priest, Father Du requested to join the Dominican Order and made his vows on December 21, 1814. Later, he was transferred to serve at Lieu De parish, now part of Bui Chu Diocese, on May 20, 1839.
Father Du was a model example of a life of prayer, zealous in evangelization activities, and serving the faithful of the Dong Dang Ngoai Diocese.
On May 20, 1839, upon receiving news of the appearance of a Catholic leader, Governor Trinh Quang Khanh personally led troops to surround Lieu De village to search it. As Father Du had just finished Mass at Mrs. Thu's house and heard the loud shouting, realizing the village was surrounded by soldiers with no escape, he disguised himself as a hired worker and sat behind the garden pulling weeds.
A soldier pointed at him and shouted: "There, the Catholic leader!" With a calm face, Father Du acknowledged: "Yes, I am the leader. I have a duty to take care of the faithful here."
After 6 months of imprisonment and torture, with temptations to renounce the Catholic faith which did not shake his will, the authorities had to convict him and transfer him to the capital Thuan Hoa for execution on charges of "propagating the Catholic religion."
In prison, Father Dinh Viet Du was jailed with Father Nguyen Van Xuyen. The two prayed together, encouraged each other, and administered the Sacrament of Penance, preparing their souls to profess their faith before the king, mandarins, and the crowd.
On November 26, 1839, Father Dinh Viet Du was executed by beheading at the Bay Mau court under King Minh Mang's reign. His martyred remains are venerated at the Phu Nhai Martyr's Memorial.
Father Thomas Dinh Viet Du was beatified on May 27, 1900 and canonized on June 19, 1988.