He was born at Burnham in Norfolk, the son of the vicar of the parish. He was educated at Eton College and King's College, Cambridge, and in 1814 was appointed assistant master at Eton under Dr John Keate. In 1834 he became headmaster of Eton. Under his administration, new buildings were erected, including the school library and the sanatorium, the college chapel was restored, the Old Christopher Inn was closed, and the custom of Montem, the collection by street begging of funds for the university expenses of the captain of the school, was suppressed.
Hawtrey is supposed to have suggested the modern language prizes given by Prince Albert, and himself founded the prize for English essay. In 1852 he became provost of Eton, and in 1854 vicar of Mapledurham. He was buried in the Eton College chapel.
On account of his command of languages, he was known in London as the English Mezzofanti, and he was a book collector of the finest taste. Among his own books are some excellent translations from the English into Italian, German and Greek. He had a considerable reputation as a writer of English hexameters and as a judge of Homeric translation: his translation of a brief passage from the Iliad was described by Matthew Arnold, in On Translating Homer, as "the most successful attempt hitherto made at rendering Homer into English".