Alan of Walsingham (died c. 1364), also known as Alan de Walsingham, was an English architect, first heard of in 1314 as a junior monk at Ely, distinguished by his skill in goldsmith's work, and for his acquaintance with the principles of mechanics.
He afterwards turned his attention to the study of architecture, and in 1331, when sub-prior of his convent, designed and began to build St Mary's Chapel (now Trinity Church), attached to the cathedral of Ely. At the same time he was engaged in the erection of Prior Crauden's Chapel, the new sacristy, and many minor works. In December 1321, he was elected sacristan, with sole charge of the fabric of the cathedral.
In February 1322, the great tower of the Ely Cathedral fell, and destroyed the choir and other attached portions of the structure. Instead of rebuilding the four piers, which carried the Norman (square) tower, a weak point in cathedral construction, Alan advanced the supports, to the extent of one bay, into each arm of the cross; and by so doing he not only distributed the weight upon eight piers instead of four, but obtained a magnificent central octagonal hall, which he roofed with a dome surmounted by a tall lantern. The result was not only very beautiful, but also very original. It is almost certain that Alan never traveled beyond the limits of his convent, and that he was not acquainted, except perhaps from hearsay, with the domed Churches of the East, whose principles of construction, moreover, differ essentially from those employed by Alan. His work remains to this day unique among the cathedrals of Europe. He subsequently rebuilt the bays of the choir, which had been ruined by the fall of the great tower, and these are admittedly amongst the most beautiful examples of Decorated, or Second Pointed, English Gothic architecture.
In 1341, Alan of Walsingham was elected prior of his convent, and in 1344 to the bishopric of Ely, rendered vacant by the death of Simon de Montacute. When he thus became bishop-elect, the works connected with the fabric of the cathedral had been conducted to a successful termination, leaving for his successor only the decorations and fittings.