Mary Madeline "May" Bonfils Stanton (April 30, 1883 – March 11, 1962) was an American heiress and philanthropist.
She and her younger sister, Helen Bonfils, succeeded their father, Frederick Gilmer Bonfils, as principal owners of The Denver Post.
However, May's elopement at age 21 with a non-Catholic salesman had forged a rift in her relationship with her parents and sister that worsened when Helen inherited the lion's share of their parents' estates.
Following a three-year legal battle over the inheritance, the sisters cut off all communication with each other.
May married twice but did not have children.
Living a reclusive life, she invested her fortune into building and furnishing her 750-acre (300 ha) estate in Lakewood, Colorado – which included a mansion that was an exact replica of Marie Antoinette's Petit Trianon château in Versailles – and into many philanthropic endeavors in the state of Colorado.
The Bonfils–Stanton Foundation, established by her second husband after her death in 1962, continues to support the arts in Colorado.
She was posthumously inducted into the Colorado Women's Hall of Fame in 1985.