Thomas Blount (1618–1679) was an English antiquarian and lexicographer.
He was the son of Myles Blount of Orleton in Herefordshire and was born at Bordesley, Tardebigge, Worcestershire. He was called to the bar at the Inner Temple, but, being a zealous Roman Catholic, his religion interfered considerably with the practice of that profession at a time when Catholics were excluded from almost all areas of public life in England. Retiring to his estate at Orleton, he devoted himself to the study of the law as an amateur, and also read widely in other branches of knowledge.
Thomas Blount married Anne Church of Maldon, Essex (1617–1697) in 1661 and they had one daughter, Elizabeth (1662–1724). He died on December 26, 1679, at Orleton, Herefordshire, at the age of sixty-one.
His principal works include Glossographia; or, a dictionary interpreting the hard words of whatsoever language, now used in our refined English tongue (1656), which went through several editions and remains amusing and instructive reading. It defined around 11,000 hard or unusual words, and was the largest English dictionary when it was published. His was the last, largest, and greatest of the English "hard-word" dictionaries, which aimed not to present a complete listing of English words, but to define and explain unusual terms that might be encountered in literature or the professions, thus aiding the burgeoning non-academic middle class, which was ascendant in England at the time and of which Blount was a member. Glossographia marked several "firsts" in English lexicography. It was the first dictionary that included illustrations (two woodcuts of heraldic devices) and etymologies, and the first that cited sources for definitions. It contained many unusual words that had not previously been included in dictionaries, and others not included in any later dictionary. While some of these were neologisms, Blount did not coin any words himself, but rather reported on the rather inventive culture of classically inspired coinages of the period.