Joseph Gwilt (January 11, 1784 - September 14, 1863), English architect and writer, was the younger son of George Gwilt, architect surveyor to the county of Surrey, and was born at Southwark.

He was educated at St Paul's School, and after a short course of instruction in his father's office was in 1801 admitted a student of the Royal Academy, where in the same year he gained the silver medal for his drawing of the tower and steeple of St Dunstan-in-the-East. In 1811 he published a Treatise on the Equilibrium of Arches, and in 1815 he was elected FSA.

After a visit to Italy in 1816, he published in 1818 Notitia architectonica italiana, or Concise Notices of the Buildings and Architects of Italy. In 1825 he published an edition of Sir William Chambers's Treatise on Civil Architecture; and among his other principal contributions to the literature of his profession are a translation of the Architecture of Vitruvius (1826), a Treatise on the Rudiments of Architecture, Practical and Theoretical (1826), and his valuable Encyclopaedia of Architecture (1842), which was published with additions by Wyatt Papworth in 1867.

In recognition of Gwilt's advocacy of the importance to architects of a knowledge of mathematics, he was in 1833 elected a member of the Royal Astronomical Society. He took a special interest in philology and music, and was the author of Rudiments of the Anglo-Saxon Tongue (1829), and of the article "Music" in the Encyclopaedia metropolitana. His principal works as a practical architect were Markree Castle near Sligo in Ireland, and St Thomas's church at Charlton in Kent.