Charles Sherlock Fillmore (August 22, 1854 – July 5, 1948) founded Unity, a church within the New Thought movement, with his wife, Myrtle Page Fillmore, in 1889. He became known as an American mystic for his contributions to spiritualist interpretations of biblical Scripture.

He was born in St. Cloud, Minnesota on August 22, 1854.

An ice skating accident when he was ten broke Fillmore's hip and left him with lifelong disabilities. In his early years, despite little formal education, he studied Shakespeare, Tennyson, Emerson and Lowell as well as works on spiritualism, Eastern religions, and metaphysics.

He met his future wife, Mary Caroline "Myrtle" Page, in Denison, Texas in the mid-1870s. After losing his job there, he moved to Gunnison, Colorado where he worked at mining and real estate.

He married Myrtle in Clinton, Missouri on March 29, 1881 and the newlyweds moved to Pueblo, Colorado, where Charles established a real estate business with the brother-in-law of Nona Lovell Brooks, who was later to found the Church of Divine Science.

After the births of their first two sons, Lowell Page Fillmore and Waldo Rickert Fillmore, the family moved to Kansas City, Missouri. Two years later, in 1886, Charles and Myrtle attended New Thought classes held by Dr. E. B. Weeks. Myrtle subsequently recovered from chronic tuberculosis and attributed her recovery to her use of prayer and other methods learned in Weeks's classes. Subsequently, Charles began to heal from his childhood accident, a development which he too attributed to following this philosophy. Charles Fillmore became a devoted student of philosophy and religion.

In 1889, Charles and Myrtle began publication of a new periodical, 'Modern Thought', notable among other things as the first publication to accept for publication the writings of the then 27-year-old New Thought pioneer William Walker Atkinson. In 1890, they announced a prayer group that