Gillette Hayden was born on March 2, 1880, in Greenville, Florida. Her family eventually moved to Columbus, Ohio, where Gillette Hayden graduated as valedictorian from East High School. Upon graduating, Hayden enrolled at The Ohio State University. In 1902, she became only the third woman to graduate from Ohio State's dental school. She studied briefly at Northwestern University in Evanston, Illinois, before returning to Columbus to establish her own dental practice in 1903.
Over the course of her career, Hayden became known as an expert in the treatment of periodontal diseases. From 1905 until 1908, she traveled throughout Europe, educating dentists about new ways to treat periodontal diseases. Upon returning to Columbus in 1908, Hayden devoted her practice solely to the treatment of these diseases.
To help educate other dentists regarding periodontal diseases and their treatment, Hayden, in conjunction with Grace Rogers Spalding, established the American Academy of Periodontology in 1914. Hayden served as this organization's president in 1916. Hayden also became president of the Federation of American Women Dentists in 1923 and was elected secretary of the periodontia section of the International Dental Congress in 1925.
In her free time, Hayden also became a champion of women's rights. In 1925, she won election as president of Altrusa International, Inc., a service organization for professional women.
Sadly, Hayden died on March 27, 1929, at only forty-nine years of age.