Frank Jeremiah Armstrong (April 15, 1877 – November 2, 1946) was an American physician who was the first African-American graduate of Cornell College. He was the assistant of Booker T. Washington and later became a physician. He was murdered in his office in 1946, possibly by a burglar after a hospital's narcotics.

Armstrong graduated in 1900 from Cornell College as the first African American to do so.^[1] His nickname at Cornell was "Buck". He began playing baseball as a part of the Marion Ravens when he was 13 years old, and he played during the 1890s.^[2] Armstrong was a part of the college's Adelphian Literary Society and was a secretary of the society for one spring. In 1900, his final year in college, he was the captain of the baseball team. Booker T. Washington was announced as a speaker by Armstrong during the commencement ceremony, leading to Washington hiring Armstrong as his assistant.^[1] He received a medical degree from the College of Physicians and Surgeons in 1912 (which became the University of Illinois College of Medicine in 1913). Armstrong became a physician in Chicago. He was a part of the Chicago Medical Society, the American Medical Association, and the National Medical Association.^[3]

Armstrong married Jessie Marie Lucas in Chicago, on December 22, 1915. They had no children.

His college commencement address is in the 1905 book A Record of the Celebration of the Fiftieth Anniversary of the Founding of the College, published by Cornell College.^[4]

Armstrong was murdered in his office by gunshot on November 2, 1946, when he was 69 years old by a suspected burglar, but nothing was stolen.^[3] His body was found by a patient who called for help.^[5][6] He was survived by his wife Jessie Marie Armstrong and a $1,000 reward was offered by the police.^[3] It was later suspected that the murderer was part of a group after a narcotics safe at Providence hospital.^[7]

A student residential house and community center on the campus of Cornell College was named in his honor in 2010.^[8][9]