She was born in 1656 on the south bank of the Mohawk River, in a village called Ossernenon. 

When she was four years old, a smallpox epidemic claimed the lives of her parents and baby brother. Their names are unknown. 

Tekakwitha survived the disease but her eyesight was impaired. Her face was scarred and the disease left her weak the rest of her life. After about five years of the sickness, the survivors of the village moved to the north bank of the river to begin a new life. Tekakwitha and her relatives moved into the turtle clan village called Gandauoque (Caughnawaga). 

The first time she saw a priest was in 1667 when Fathers Fremin, Bruyas and Pierron visited Caughnawaga. 

In 1670, St. Peter's Mission was established in Caughnawaga (Fonda, NY). A chapel was built inside one of the longhouses. In 1674, Fr. James de Lamberville took charge of St. Peter's Mission. 

Tekakwitha met Fr. De Lamberville a year later when he visited her home. She told him about her desire to become baptized. She began to take religious instruction, and in 1676, April 5th, on Easter Sunday, she was baptized and given the name Kateri or Katherine. 

In August of 1677, Kateri fled her village to go and live at Sault St. Louis, St. Francis Xavier Mission near Montreal. 

Two months later and about two hundred miles through woods, rivers and swamps, Kateri arrived at the Sault with the help of friends. 

On Christmas Day, 1677, Kateri received her first Holy Communion. 

During a winter hunt, Kateri was falsely accused of sinful relations with a hunter. 

Mary Teresa (Tegaiaguenta) and Kateri became friends. Both girls performed extraordinary penances. Kateri and her friend asked permission to start a religious community. Request was denied. 

In 1678, Kateri enrolled in the pious society called The Holy Family because of her extraordinary practices of all virtues. 

On March 15, 1679, at the Feast of the Annunciation, a moment after receiving Holy Communion, Kateri pronounced her vow of perpetual virginity. 

Her whole life was devoted to teaching prayers to the children and helping the sick and the aged until she was struck with an illness that was to claim her life. 

On April 17th, 1680, on Wednesday of Holy Week, she died at 3 o'clock in the afternoon at the age of twenty-four. Her last words were: "Jesos Konoronkwa". "Jesus I Love You". Fifteen minutes after her death before the eyes of two Jesuits and all the Indians that could fit into the room, the ugly scars on her face suddenly disappeared. 

On January 3, 1943, she was declared Venerable by Pope Pius XII.