American literary scholar and teacher, one of the foremost authorities of his time on the writings of Shakespeare (Shakespeare, William), Chaucer (Chaucer, Geoffrey), and Sir Thomas Malory.

As a teacher, Kittredge was both the terror and delight of undergraduate students, conducting his year-long course in Shakespeare as a painstaking, line-by-line study of six plays. He taught his graduate courses in a less dramatic and more scholarly way. His major writings, along with many journal articles, established him as the then preeminent U.S. scholar of English literature.

After Kittredge received his A.B. degree at Harvard in 1882, he taught Latin at Phillips Exeter Academy (New Hampshire, 1883–88), with a year off for study abroad. He returned to teach at Harvard in 1888 and remained there until his retirement in 1936 (from 1917 as the first Gurney Professor of English). He was a protégé of Francis J. Child (Child, Francis J), the English and Scottish popular-ballad scholar, whose course in English Kittredge took over after his mentor's death in 1896. As a teacher Kittredge was known for his brilliant, discursive style. He was also noted for his sharp wit and impressive personal manner.

Chaucer and His Poetry (1915) was acclaimed as one of the first works to make clear Chaucer's greatness to modern readers. Other books include A Study of Gawain and the Green Knight (1916); Words and Their Ways in English Speech (1901), with J.B. Greenough; Witchcraft in Old and New England (1929); and a notable edition of The Complete Works of Shakespeare (1936).