Educated at Repton, whence he proceeded to the University of Aberdeen, he became in 1817 vicar of Little Horwood, Buckinghamshire, and devoted his spare time to literature and particularly to the study of Anglo-Saxon. In 1823 appeared his Elements of Anglo-Saxon Grammar.
In 1829 Bosworth went to Holland as chaplain, first at Amsterdam and then at Rotterdam. He remained in Holland until 1840, working there on his Dictionary of the Anglo-Saxon Language (1838), his best-known work.
In 1857 he became rector of Water Stratford, Buckinghamshire, and in the following year was appointed Rawlinsonian Professor of Anglo-Saxon at Oxford. He gave to the University of Cambridge in 1867 £10,000 for the establishment of a professorship of Anglo-Saxon. He died leaving behind him a mass of annotations on the Anglo-Saxon charters, and is buried in Water Stratford churchyard. The Oxford professorship was held by JRR Tolkien from 1925 to 1945, by which time it was known as the Rawlinson and Bosworth Professorship of Anglo-Saxon.