Charles Horace Mayo

Charles Horace Mayo (1865 – 1939) was a United States medical practitioner and a co-founder of the Mayo Clinic.

Mayo graduated from Chicago Medical College in 1888 and joined his father (William Worrall Mayo and older brother William J. Mayo) in their medical practice in Rochester, Minnesota. In 1889, the Mayos opened the first general hospital in southeastern Minnesota and pioneered the principle of 'group practice'. The Mayo Clinic came to be regarded as one of the foremost medical treatment and research institutions in the world. Within Mayo's lifetime it registered one million patients.

As far as he could within a general practice, Mayo specialized in surgery of the thyroid and nervous system. He was also responsible for the clinic's opthalmic patients until 1908. In the face of his father's resistance, he and his brother insisted on sterile conditions in the operating room and he was also an early adopter of X rays as a diagnostic tool.

Mayo was an active freemason like his father. He was initiated on January 27 1890 and raised to the degree of Master Mason on May 12 1890 in Rochester Minnesota Lodge No. 21.

Mayo retired in 1928 and died in 1939. His son Charles William Mayo continued his work in the clinic.

The US Post Office printed a stamp depicting him and his brother on September 11 1964.