Abstract: An adjustable arch support for use in brick and other masonry construction provides temporary support of a brick or masonry arch during construction. The support provides for adjustment for both width and height, for use in masonry openings of various sizes and shades. A header includes plural fingers extending vertically upward therefrom, with the fingers also being vertically adjustable. Each of the fingers includes a brick or masonry support pivotally attached to the upper end thereof, providing for angular adjustment to properly support a brick or masonry monolith during construction of the arch. The support is adjusted horizontally and vertically to fit the lower rectangular portion of the arch opening, and the fingers are adjusted vertically to form the proper arch shape. One or several more masonry courses may then be constructed, using the arch support for support until the mortar or cement has cured.