A man named Ugolino became Pope Gregory IX at, reportedly, 86 years old in 1227.
However, some historians set his birth date as only “before 1170”; others say “around 1145.”
Before his papal appointment, he had a long career as a deeply devoted theologian, diplomat, and lawyer and was said to be close friends with St. Francis of Assisi.
He held the office for about 13-and-a-half years, dying at a really ripe old age. Most popes seem to be really old men.