a painter and writer of some eminence in his day, was born in the parish of St James's, Garlickhithe, London, on the 13th of June 1692, being the third son of Mr Edward Highmore, a coal-merchant in Thames Street. Having such an early and strong inclination to painting that he could think with pleasure of nothing else, his father endeavoured to gratify him by making a proposal to his uncle, who was sergeant-painter to King William, and with whom Mr, afterwards Sir James Thornhill, had served his apprenticeship. This however was subsequently for good reasons declined, and he was articled as clerk to an attorney in 1707, but so much against his own declared inclination, that in about three years he began to form resolutions of indulging his natural disposition for his favourite art, having continually employed his leisure hours in designing, and in the study of geometry, perspective, architecture, and anatomy, but without any instructors in these branches except books. He had afterwards an opportunity of improving himself in anatomy, by attending the lectures of Mr Cheselden; besides entering himself at the painters' academy in Great Queen Street, where he remained ten years, and had the honour to be particularly noticed by Sir Godfrey Kneller, who distinguished him by the name of the Young Lawyer. In 1714 his clerkship expired; and in 1715 he began painting as a profession, and settled in the city. In the same year Dr Brook Taylor published his Linear Perspective. On this complete and universal theory our artist grounded his subsequent practice; and it has been generally allowed, that few if any of the profession at that time were so thorough masters of Taylor's excellent but intricate system. In 1716 he married Susanna, daughter and heiress of Mr Anthony Hiller of Ellingham, in Surrey; a young lady in every respect worthy of his choice. As his reputation and business increased, he took a more conspicuous station, by removing to a house in Lincoln's-Inn-Fields; and an opportunity soon offered of introducing him advantageously to the nobility, by his being desired, by Mr Pine the engraver, to make drawings for his prints of the knights of the bath, upon the revival of that order in 1725. The publication of Pamela in 1744 gave rise to a set of paintings by Highmore, which were engraved by two French engravers, and published by subscription in 1745. In the same year he painted the only original of General Wolfe, who was then about eighteen years of age. His Pamela introduced him to the acquaintance and friendship of the excellent author of that work, whose picture he drew, and for whom he painted the only original of Dr Young. In 1750 he had the misfortune to lose his wife. On the first institution of the Academy of Painting and Sculpture, in 1753, he was elected one of the professors; an honour which, on account of many avocations, he was induced to decline. In 1754 he published a critical examination of two paintings by Rubens on the ceiling of the banqueting-house at Whitehall, in which architecture Highness is introduced, as far as relates to perspective; together with the discussion of a question which has been the subject of debate amongst painters: printed in 4to. Of the numerous portraits which Mr Highmore painted, in an extensive practice of forty-six years, it is impossible and useless to discuss the merits. Some of the best in the historical branch may, however, be mentioned, viz. Hagar and Ishmael; the Good Samaritan; the Finding of Moses; the Harlowe Family, as described in Clarissa; Clarissa, the portrait mentioned in that work; the Graces Unveiling Nature; the Clementina of Grandison; and the Queen Mother of Edward IV. with her younger son, in Westminster Abbey.

His principal literary work was his Practice of Perspective, on the principles of Dr Brook Taylor, written many years before, but not published till 1763. In 1765 he published Observations on a Pamphlet entitled Christianity not founded on Argument; and in the same year two small volumes of Essays, moral, religious, and miscellaneous, with a translation in prose of Mr Brown's Latin poem on the immortality of the soul. A strong constitution, and constant attention to his health, prolonged his life and preserved his faculties until his eighty-eighth year, when he gradually ceased to breathe, and, as it were, fell asleep, on the 3d of March 1780.