Saint Thérèse of Lisieux (January 2, 1873 – September 30, 1897), or Saint Thérèse of the Child Jesus and the Holy Face, born Marie-Françoise-Thérèse Martin, was a French Carmelite nun. She is also known as "The Little Flower of Jesus" or simply, "The Little Flower".

She has been a highly influential model of sanctity for Roman Catholics and for others because of the "simplicity and practicality of her approach to the spiritual life." Together with St. Francis of Assisi, she is one of the most popular saints in the history of the church. Pope Pius X called her "the greatest saint of modern times."

Therese felt an early call to religious life, and overcoming various obstacles, in 1888 at the early age of 15, she became a nun and joined two of her elder sisters in the cloistered Carmelite community of Lisieux, Normandy. After nine years as a Carmelite religious, having fulfilled various offices such as sacristan and assistant to the novice mistress, and having spent her last eighteen months in Carmel in a night of faith, she died of tuberculosis at the age of 24.

The impact of The Story of a Soul, a collection of her autobiographical manuscripts, printed and distributed a year after her death to an initially very limited audience, was great, and she rapidly became one of the most popular saints of the twentieth century. Pope Pius XI made her the "star of his pontificate". She was beatified in 1923, and canonized in 1925. Thérèse was declared co-patron of the missions with Francis Xavier in 1927, and named co-patron of France with Joan of Arc in 1944. On October 19, 1997 Pope John Paul II declared her the thirty-third Doctor of the Church, the youngest person, and only the third woman, to be so honored. Devotion to Thérèse has developed around the world.