Lewis, best known as an editor of Shakespeare, was the son of an attorney practising at Sittingbourne in Kent. His grammatical learning he received at Isleworth in Middlesex, and was originally destined for his Theocritus, father's business; but this he speedily abandoned for the profession of an author, and having fixed his residence in the metropolis, he engaged in a variety of literary undertakings. To Mist's Weekly Journal he contributed a paper called "The Censor;" and his censures being pronounced with great freedom, gave no small offence to some writers more formidable than himself: One of those whom he provoked was the raider Dennis. Pope's translation of Homer he at first extolled, and afterwards abused. He was the original hero of the Dunciad, but was displaced to make room for Gibber, to whom the poet's satire is in many instances inapplicable. Theobald endeavoured to avenge himself by publishing Shakespeare restored; or, a Specimen of the many Errors as well committed as unamended by Mr Pope in his edition of this poet, designed not only to correct the said edition, but to restore the true Reading of Shakespeare in all the editions ever yet published, Lond. 1726, 4to. This prelude was, after a considerable interval, followed by his edition of Shakspeare's Works, Lond. 1733, 7 vols. 8vo. In 1726 he had introduced on the stage The Double Falsehood, or, the Distrest Lovers, of which, as he averred, the greater part was written by Shakespear. His arguments in favour of this hypothesis were not considered as satisfactory; and, according to the opinion of Dr Farmer, this drama was the production of Shirley. Theobald was the author or translator of twenty plays, enumerated in the Biographia Dramatica, vol. i., p. 706. He was likewise concerned in various translations; and at the time of his death he had made some progress in an edition of Beaumont and Fletcher. He died in the month of September 1744.