Adelaide Crapsey was born on September 9, 1878 to Algernon Sidney and Adelaide Trowbridge Crapsey in Rochester, NY. She attended the Kemper Hall preparatory school in Kenosha, WI and graduated first in her class in 1897. Upon graduating, she entered Vassar College and matriculated with the class of 1901.

In 1903, Crapsey returned to Kemper Hall as a teacher of history and literature. In 1905 she studied at the School of Archeology in Rome, and following her return to the United States the next year, she became an instructor of history and literature in Miss Lowe's Preparatory School in Stamford, CT. However, her health was suffering from the effects of tuberculosis, and she was forced to stop teaching in 1908. She spent much of this time in Italy and England, working on her book, Analysis of English Metrics, which she considered her serious life work. Crapsey was also a talented poet, and invented her own metrical form, the cinquain. In 1911, Crapsey accepted a position as Instructor of Poetics at Smith College. In 1913 she became gravely ill and had to abandon her literary and academic work. She retreated to Saranac Lake in New York, where she died on October 8, 1914. She was 36 years old.

A book of poetry, Verse, was published posthumously by her parents in 1915 as well as the unfinished work A Study in English Metrics, in 1918.