Stanley Francis Rother was born on March 27, 1935, in Okarche, Oklahoma. The oldest of the four children born to Franz and Gertrude Rother, he grew up on the family farm, rising before dawn to milk cows, working the land alongside his father, and attending Holy Trinity Catholic Church, the parish that had anchored his family's faith for generations. He played basketball, served as an altar server, and was president of the Future Farmers of America in high school. By every measure, his was an ordinary Oklahoma childhood, shaped by hard work, community and a quiet but deep Catholic faith.

While in high school, he began to discern the possibility of a vocation to the priesthood. He was accepted as a seminarian and was sent to Assumption Seminary in San Antonio, Texas. After several academic struggles and setbacks, particularly struggling to learn Latin, he ultimately completed his studies at Mount Saint Mary’s Seminary in Emmitsburg, Maryland, and was ordained a priest for what was then the Diocese of Oklahoma City and Tulsa on May 25, 1963.

At his ordination, Father Stanley chose St. Augustine's motto as his own: "For my benefit I am a Christian, for the benefit of others I am a priest."

Only a few years after his ordination in 1963, he answered Pope John XXIII's call to send missionaries to Central America and joined the Oklahoman mission in Santiago Atitlán, Guatemala, where he served the indigenous Tz'utujil people.