William Melmoth the younger (c.1710–1799) was an English lawyer and man of letters.
He was the son of William Melmoth the elder and his second wife, Catherine Rolt, was probably born in London, and was baptised in 1710. He was schooled in Westminster, and entered Lincoln's Inn in 1724. He matriculated at Magdalene College, Cambridge in 1726.
At the close of the 18th century, Melmoth was a familiar figure in Bath literary society. He died at No. 12 Bladud's Buildings, Bath, on 13 May 1799. There was a Latin epitaph placed on a tablet in Bath Abbey; but Melmoth was buried at Batheaston.
- Letters on Several Subjects, 1742, under the pseudonym "Sir Thomas Fitzosborne". Fitzosborne's Letters, vol. 2, appeared in 1747, with a translation of the De Oratoribus of Tacitus.
- Letters of Pliny the Younger, 1746, translator; praised by Thomas Birch and Thomas Warton. A second edition was printed in 1747, a third in 1748. In 1791 Jacob Bryant attacked Melmoth for asserting in this work that the persecution under Trajan was due to the principles of the Roman state; Melmoth replied in a pamphlet of 1793.
- Ad Familiares by Cicero, 1753, translator.
- De Senectute by Cicero, 1773, translator.
- De Amicitia, translator.
- Memoir of a late eminent Advocate, 1796, on William Melmoth the elder.
Samuel Johnson was not impressed with Melmoth, regarding him as no threat. As he told Hester Thrale, he had once "in some small dispute reduced him to whistle". Thomas De Quincey, who was offered a chance to view his manuscripts around 1813, opined that "Melmoth was a fribble in literature". On the other hand, William Coxe praised him as a literary guide.
- Wilson, Penelope. "Melmoth, William, the younger". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/18536. (Subscription or UK public library membership required.)
- "William Melmoth (MLMT726W)". A Cambridge Alumni Database. University of Cambridge.
- Lee, Sidney, ed. (1894). . Dictionary of National Biography. 37. London: Smith, Elder & Co.